This case is before the Court for a second time. In the prior appeal, P.R. v. Shannon, 726 P.2d 500 (Wyo.1986), we reversed and remanded a decision terminating the parental rights of PR, due to the failure to appoint a guardian ad litem to represent the best interests of the minor children in the termination proceeding. The instant appeal is from an order of the district court which, upon the motion of the State of Wyoming, Division of Public Assistance and Social Services, dismissed the petition for termination of parental rights but upheld the validity of relinquishments of custody and consents for adoption previously executed by appellant PR in relation to her minor children, TR and JS. In resolving the issues presented in this appeal, we must examine the validity of the relin-quishments and consents for adoption, including the effect of appellant’s attempted revocation thereof, and determine whether the procedural mechanisms involved in this case were sufficient to free these children for adoption.
We affirm.
Appellant presents these issues:
1. [WHETHER] THE TRIAL COURT ERRED WHEN IT APPLIED AN IMPROPER STANDARD TO DETERMINE WHETHER OR NOT A RELINQUISHMENT OF PARENTAL RIGHTS WAS VALID.
2. [WHETHER] THE TRIAL COURT ERRED WHEN IT FAILED TO APPLY THE FACTS DEVELOPED TO THE PROPER STANDARD.
The Big Horn County Department of Public Assistance and Social Services (DPASS) first became involved with appellant in 1976 or 1977 when it arranged for her placement in the Job Corps. In 1981, while unmarried and pregnant with TR, appellant was referred to DPASS by a physician who was concerned about her ability to adequately care for the child. DPASS unsuccessfully attempted to persuade ap*1108pellant to relinquish the baby for adoption. TR was born in October of 1981. Appellant did not marry TR’s father. Thereafter, DPASS provided various services to appellant, primarily involving public assistance benefits. Appellant subsequently married, and a second child, JS, was born in early 1983.1 In September 1983, DPASS received a child abuse complaint regarding TR, and from that point forward DPASS became actively involved in attempting to improve appellant’s parenting skills in order that she could properly care for her children.
Efforts by DPASS to improve appellant’s abilities as a parent and to protect the children included parenting classes, mental health counseling, protective day care, and temporary foster care for the children. These efforts were largely unsuccessful, however, as continued incidents of neglect and complaints of abuse were documented. Beginning in the fall of 1984, as a result of the continuing problems, appellant’s DPASS caseworker began discussing with appellant the possibility or option of relinquishing her children for adoption. In October of 1984, appellant was not willing to relinquish her children for adoption but she did agree to a voluntary thirty-day foster placement for them. In the ensuing months, appellant’s mental health counsel- or also discussed with her the possibility of relinquishing her children for adoption.
As further incidents and complaints of neglect and abuse occurred, it became apparent to the agencies involved that efforts on behalf of appellant and her children were not succeeding and that more drastic measures might be needed. These concerns were communicated to appellant. Finally, during a counseling session with her mental health counselor on May 24, 1985, appellant declared she was ready to relinquish the children for adoption. Her mental health counselor telephoned the caseworker, informed her of appellant’s decision, and then transported appellant to the DPASS office where appellant executed relinquishment and consent for adoption documents for both children in the presence of her mental health counselor, the caseworker, and a notary public. Physical relinquishment of the children occurred later that day.
A few days later, appellant called the DPASS office and indicated she wished to revoke the relinquishments, and this telephone call was followed by a letter to the same effect dated June 4, 1985. In her telephone call and letter, appellant indicated that she had not fully understood the consequences of relinquishment and that she wanted her brother and sister-in-law in Alaska to adopt the children.
In an action apparently reflecting some uncertainty regarding the validity of the relinquishments and consents for adoption, DPASS filed a petition on June 28, 1985, seeking termination of appellant’s parental rights and those rights of the children’s fathers. Following a hearing held February 4 and 5, 1986, the district court entered its order terminating appellant’s parental rights on the basis of neglect and failure of efforts to rehabilitate pursuant to Wyo. Stat. § 14-2-309(a)(iii) (1977). The district court also terminated the parental rights of TR’s father by default on the basis of his election, as communicated to the court by his appointed counsel, not to appear and contest. JS’ father had been dismissed from the termination action pursuant to his motion to dismiss, presented at the close of the State’s case, upon the district court’s finding that the State had failed to present clear and convincing evidence that he was unfit to have custody of JS. As previously mentioned, the termination decision was overturned by this Court on the procedural ground that a guardian ad litem had not been appointed to represent the interests of the children as required in termination proceedings by this Court’s decision in DB v. MM, 617 P.2d 1078 (Wyo.1980), and by Wyo.Stat. § 14-3-211(a) (1977).2
*1109Mandate on reversal issued from this Court on October 28, 1986. On November 17, 1986, the State/DPASS filed a motion to dismiss the termination proceedings on the ground that the voluntary relinquish-ments and consents to adoption had effectively extinguished appellant’s parental rights, thereby rendering termination proceedings unnecessary. The State also noted in this motion that JS’ father had executed a relinquishment with respect to JS since the original hearing. Appellant resisted the motion to dismiss, indicating to the district court that she should have a forum in which to challenge the validity of the consents. An attorney was appointed as guardian ad litem for the children. Thereafter, upon the stipulation of the parties, the district court allowed appellant to amend her answer to the original termination petition by adding a counterclaim for declaratory relief regarding the validity of the relinquishments. The district court’s September 25, 1987, order granting appellant leave to amend her answer effectively provided for a bifurcated hearing in which the validity of the relinquishments would be considered as a threshold matter.
The matter was heard on January 6 and 7, 1988, and the district court, in its subsequent decision letter and order, found the relinquishments and consents to adoption executed by appellant to be valid and binding. The termination proceedings, consequently, were dismissed. This appeal followed. This Court, upon its own motion, noted that the order appealed from did not dispose of the claims relating to the two fathers and remanded for entry of a final order with respect to those claims. Accordingly, the district court entered an order indicating that the parental rights of the fathers had previously been resolved. The district court noted that JS’ father had signed a voluntary relinquishment with respect to JS and that the parental rights of TR’s father to TR were terminated by the original order in this case, from which he did not appeal.
Appellant’s primary contention in this appeal is that the district court applied an improper standard in determining whether or not the relinquishments executed by appellant were valid. We cannot agree.
We first observe that this action is predicated on the Wyoming adoption statutes, Wyo.Stat. §§ 1-22-101 to -116 (1977), and not on the termination of parental rights statutes, Wyo.Stat. §§ 14-2-308 to -319 (1977). In PAA v. Doe, 702 P.2d 1259 (Wyo.1985), we observed that the adoption statutes and termination statutes do not serve identical purposes and, therefore, they are subject to different standards. We have also stated that “consent lies at the foundation of statutes of adoption and that the first duty of the judge is to see that all necessary consents are given.” MVF v. MF, 766 P.2d 550, 552 (Wyo.1988).
As it existed in relation to this case, § 1-22-109, entitled “Consent to adoption,” provided:3
(a) A written relinquishment of the child and written consent to adoption shall be filed with the petition to adopt and shall be signed by:
(i) Both parents, if living; or
(ii) The surviving parent; or
(iii) The mother and putative father of the child if the name of the putative father is known; or
(iv) The mother alone if she does not know the name of the putative father, in which case she shall sign and file an affidavit so stating; or
(v) The legal guardian of the person of the child if neither parent is living or if parental rights have been judicially terminated; or
(vi) The executive head of the agency to whom the child has been relinquished for adoption, or the state board of charities and reform if the child has been committed to the Wyoming state children’s home and has been maintained by or in said home for *1110a period of one (1) year prior to the filing of the petition for adoption; or
(vii) The person having exclusive legal custody of the child by court order; or
(viii) The legally appointed guardian of any parent or putative father who has been adjudged mentally incompetent.
(b) If the child to be adopted is over the age of fourteen (14) years his written consent to adoption shall also be filed with the petition to adopt.
(c) The consent may be signed at any time and shall be acknowledged before a notary public, an officer authorized to take acknowledgments, or by a representative of the division of public assistance and social services within the department of health and social services or of a certified agency to whom the child is being relinquished for adoption, or a consent may be approved by the court after the person giving his consent has appeared before the court in an informal hearing in court chambers and if the court finds that the consent is knowingly and voluntarily given.
(d) Consent to adoption and the relinquishment of a child for adoption are irrevocable unless obtained by fraud or duress, except that if the court should deny the adoption on account of a claim or objection of the putative father of the child, the court may also allow the mother of the child to withdraw her consent and relinquishment. The consent or relinquishment by a parent who is a minor is valid and may not be revoked solely because of minority.
(Emphasis added.)
The question before us is whether the consents executed by appellant are valid. Appellant’s challenge to the validity of the consents focuses on subsection (d) of the statute regarding revocability of consents. Appellant contends that the district court improperly limited its consideration of the grounds for revocation of consent to fraud and duress and erroneously failed to consider undue influence. We observe, however, that the district court in fact did address and reject appellant’s claim of undue influence, although it did so after indicating doubt as to whether such consideration was required under the statute. The State, on the other hand, persuasively argues that courts are not free to graft a new standard onto the statute and thus consideration of undue influence was unnecessary and improper.
Adoption was unknown at common law, and adoption statutes are subject to strict construction. MVF, 766 P.2d at 552; SKMD v. SLM, 652 P.2d 974 (Wyo.1982). Additionally, since adoption is entirely statutory, the proceedings must be conducted in substantial conformity with the statutory provisions. MVF, 766 P.2d at 552; Lucas v. Strauser, 65 Wyo. 98, 196 P.2d 862 (1948). In SKMD, 652 P.2d at 978, we noted that the legislature, as a matter of public policy, provided that relinquishment of a child for adoption and consent to adoption are irrevocable, unless obtained by fraud or duress. We further noted in that case that written consent is recognized as a meaningful document which is intended to be given effect and which must not be easily set aside. Id. at 979.
This Court has said that duress exists “whenever one, by the unlawful act of another, is induced to perform some act under circumstances which deprive him of the exercise of free will.” Id. at 978. See also In re Adoption of D.P., 583 P.2d 706 (Wyo.1978), and Annotation, What Constitutes “Duress” in Obtaining Parent’s Consent to Adoption of Child or Surrender of Child to Adoption Agency, 74 A.L.R.3d 527 (1976). In SKMD, we cited the above annotation for
the general rule that where the natural parent has executed the consent after having been given an opportunity to deliberate and reflect on the decision and to seek independent advice and counseling and to ponder the alternatives available to her, duress does not exist.
652 P.2d at 978.
We recognize, however, that, although duress usually requires -wrongful circumstances, some courts have expanded *1111the meaning of duress to include “force of circumstances” and “undue influence.” See Annotation, supra, 74 A.L.R.3d at 530, and H. Clark, The Law of Domestic Relations in the United States § 21.5 at 621 (2d ed. 1987). Indeed, this Court discussed “undue influence” in In re Adoption of D.P., 583 P.2d at 708. We are not inclined, nevertheless, to expand the grounds upon which a revocation of consent to adoption may be premised. This is an area particularly within the province of the legislature. As the State correctly points out, the legislature, in recent enactments, has specifically employed the term “undue influence” in other contexts. See Wyo.Stat. § 2-6-114 (1977) regarding self-proving wills and Wyo.Stat. § 35-20-102(a)(ix) (1977) where, within the chapter on adult protective services, the legislature defines “exploitation” in relation to disabled adults as taking advantage of by, inter alia, “undue influence” or “duress.” We agree with the State that these statutes indicate that the legislature regards the terms as separate and distinct. Additionally, in Foss v. Ral-ston, 550 P.2d 481, 485 (Wyo.1976), we noted the following pertinent rules of statutory construction: (1) omission of words from a statute must be considered intentional; (2) words may not be inserted into a statute in the guise of statutory interpretation; (3) we will not supply omissions from a statute — redress being with the legislature; and (4) it is just as important to recognize what a statute does not say as what it does say. We conclude that undue influence is not a separate ground for revocation of a consent for adoption, and we need not reach the question of whether the evidence supports the district court’s finding of a lack of undue influence.
Although the foregoing effectively disposes of the precise issues formulated by appellant in this appeal, fairness to appellant requires that we address what we perceive as her underlying issue: Whether the evidence was sufficient to support the district court’s conclusion that the relin-quishments and consents were executed without fraud or duress and thus were valid. This is a factual inquiry, and our standard of review of factual questions is well settled. We will not substitute our judgment for that of the trier of fact. In re Adoption of D.P., 583 P.2d 706. We presume the findings of fact are correct, and they will be set aside on appeal only when they are clearly erroneous or contrary to the great weight of the evidence. O’s Gold Seed Company v. United Agri-Products Financial Services, Inc., 761 P.2d 673 (Wyo.1988); Yost v. Harpel Oil Company, 674 P.2d 712 (Wyo.1983). Additionally, we assume that the evidence of the prevailing party is true, leaving out of consideration the other party’s evidence in conflict therewith and giving every favorable inference to the evidence of the successful party which may fairly be drawn from it. O’s Gold Seed Company, 761 P.2d 673; DS v. Department of Public Assistance and Social Services, 607 P.2d 911 (Wyo.1980).
With respect to fraud, the district court observed in its decision letter that “[t]he evidence on fraud, if any, was so slight as to have escaped the Court’s recognition.” We agree with the district court’s conclusion that the relinquishments were not obtained by fraud, and appellant does not contend otherwise.
As previously noted, this Court has stated that duress exists whenever a person is induced, by the unlawful act of another, to perform some act under circumstances which deprive him of the exercise of free will. SKMD, 652 P.2d 974; In re Adoption of D.P., 583 P.2d 706. The district court concluded that the relinquish-ments and consents were not obtained by duress. The evidence supports that conclusion.
The record reveals that the option of relinquishment had been discussed periodically with appellant by her caseworker and by her mental health counselor for several months prior to the actual execution of the documents. These discussions reflected the ongoing failure of appellant to profit from DPASS’ efforts to intervene and improve her ability to properly care for her children. Events came to a head in the spring of 1985. On April 17th of that year, *1112DPASS received yet another complaint, apparently the third or fourth, of appellant’s child abuse or neglect. In this instance, appellant, presumably in frustration with the child’s “dawdling,” tied JS to the family dog while they were out walking, and the dog ran off dragging the child behind it, resulting in various scrapes and bruises on the child. Thereafter, the caseworker informed appellant that, if there were any further incidents involving the children’s safety, she would seek court action. On May 23, 1985, the caseworker received a physical examination report regarding the children which indicated that both children had lost weight, that both were anemic, and that their diet was “barely adequate, if that.” A decision was made within DPASS to refer the case to the county attorney for termination proceedings.
The following day appellant attended a scheduled counseling session with her mental health counselor, who had been informed of DPASS’ decision. The topic of relinquishment again arose, and appellant stated that she wanted to relinquish the children and that it would be for the best. The mental health counselor telephoned the caseworker and informed her that appellant wanted to relinquish the children. The mental health counselor then drove appellant to the DPASS office to meet with her caseworker and to execute the relinquish-ments and consents for adoption.
Appellant signed the documents in the caseworker’s DPASS office in the presence of the caseworker, the mental health counselor, and a notary public. Initially, upon arriving at the caseworker’s office, appellant expressed some reservations about relinquishing TR but, after further discussion, she decided to relinquish both children. Prior to execution of the documents, the caseworker carefully explained to appellant the significance and consequences of the relinquishments. Appellant testified that the caseworker read the documents to her word for word and that she, appellant, indicated that she understood them. Appellant testified that she was offered more time to think about it and that she was told it was not necessary for her to sign the documents that day. The caseworker testified that she repeatedly asked appellant if she was sure that this was what she wanted to do and whether she needed more time to consider the decision. Even after the relinquishments were signed, the caseworker gave appellant an opportunity to change her mind, offering to tear up the documents, but appellant declined, indicating that she was sure of her decision. It was not until after the papers had been executed that the caseworker informed appellant of DPASS’ prior decision to seek court termination. Appellant testified at trial that she understood the finality of the re-linquishments when she signed them. The caseworker picked up the children at appellant’s home on the same day that the relin-quishments were signed. The caseworker testified that appellant had the children ready to go with all their belongings packed and that appellant was calm and unemotional upon this actual physical relinquishment of her children.
The above recited evidence, with conflicts properly resolved in favor of appellee, is sufficient to support the district court’s finding that the relinquishments were obtained voluntarily and without duress. The district court correctly observed that the evidence was “completely devoid of any unlawful acts on the part of anyone which induced [appellant] to sign the relinquish-ments under circumstances which deprived her of the exercise of her free will.” The evidence further supports the district court’s observations that appellant’s actual execution of the relinquishment and consent documents “was simply a culmination of something she had been considering, both pro and con, over a long period of time” and that she “fully understood what she was doing at the time she signed the relinquishments.”
Evidence in the record also supports the district court’s conclusion that appellant’s later attempted revocation of the re-linquishments was in the nature of an ineffectual conditional revocation in that appellant did not request that the children be returned to her but rather, as the district court noted, “merely attempted to conditionally revoke the relinquishment[s] un*1113less the adoption could be carried out by her brother so that she would be able to visit the children.” Finally, testimony in the record indicates that appellant’s attempted revocation may have been partly or largely inspired by her mother’s opposition to the relinquishments.
We cannot say on this evidence that the findings of the district court are clearly erroneous or contrary to the great weight of the evidence. We hold, therefore, that the relinquishments and consents for adoption executed by appellant are valid, binding, and irrevocable pursuant to the mandates of § l-22-109(d).
At this juncture, having determined that the relinquishments and consents for adoption executed by appellant are valid, a review of the status of the children is appropriate. Appellant has relinquished both children for adoption. JS’ father has similarly executed a relinquishment and consent for adoption, and he has not subsequently challenged that relinquishment. Thus, upon issuance of this opinion, JS will be immediately available for adoption.
A different situation is presented with respect to TR and her natural father. As noted earlier in this opinion, the district court, responding to a request from this Court, entered an order relating to the claims of the fathers in which it indicated that the claims of TR’s father had been terminated by court order dated May 30, 1986, and that he did not appeal that order. That termination order, however, was reversed on jurisdictional grounds by this Court, and the failure of TR’s father to appeal from that defective order does not render it valid as to him. It will be incumbent upon the State/DPASS, in order to free TR for adoption, to either secure a relinquishment and consent to adoption from TR’s father or proceed with termination proceedings against him. In the original proceeding TR’s father notified the district court, through counsel, that he elected not to appear and proceed in the matter. Thus, under the circumstances, it might be anticipated that he will voluntarily relinquish TR for adoption.
We also note, as the culminating effect of these rather convoluted proceedings, that once a final decree of adoption is entered for these children, the remaining parental rights of the natural parents, such as they may be, will come to an end. Wyo. Stat. § 1-22-114 (1977)4. See also ALT v. DWD, 640 P.2d 73 (Wyo.1982) (decrees of adoption terminated natural father’s parental rights); Unif. Adoption Act § 14, 9 U.L.A. 58 (1971) (final decree of adoption terminates parental rights of natural parents); and H. Clark, supra, § 21.1 at 565 and § 21.4 at 606 (adoption decree ends legal rights and obligations between child and his natural parents). Cf. PAA, 702 P.2d 1259 (parental rights of nonconsenting parent terminated by operation of law pursuant to Wyo.Stat. § 1-22-110 (1977)).5 The district court’s order in this case, however, stated in part:
1. The relinquishment and consent to adoption executed by [appellant] on May 24,1985, with regard to [TR] and [JS] are valid and binding, effectively extinguishing the parental rights of [appellant] with regard to the children in question as of the date upon which said documents were executed[.]
To the extent that the order purports to formally terminate appellant’s parental rights, it is in error. Actual and final termination of parental rights can only be accomplished in Wyoming either through proceedings brought pursuant to the termination statutes or, as just discussed, upon the entry of a final decree of *1114adoption. Thus, although we affirm, we will remand to the district court with instructions to modify its order by deleting the reference to a termination of parental rights. See Gregory v. Sanders, 635 P.2d 795 (Wyo.1981), appeal after remand 652 P.2d 25 (Wyo.1982), and Allen v. Allen, 550 P.2d 1137 (Wyo.1976) (affirming but directing district court to modify judgment).
As a final matter, we should acknowledge our concern with the inordinate lapse of time involved in these proceedings from the time the consents were obtained until the subject children will finally be available for adoption. We are aware that the ability of agencies such as DPASS to find adoptive homes for specific children generally diminishes over time as the children grow older. In the instant case, the delay in placing these children in adoptive homes is the direct result of the continuous litigation since 1985 concerning the availability of the children for adoptive placement. DPASS has been precluded from placing these children in adoptive homes because of the unsettled legal status of the children. We anticipate that our decision herein regarding the validity of relinquishments and consents for adoption will avert many such problems in the future. A question arises, nevertheless, as to the duration of valid consents. In this respect, we observe that § l-22-109(d) provided that relinquish-ments and consents were irrevocable, with the limited exceptions as discussed, and the statute did not provide for any expiration of the consents if adoption had not occurred within a prescribed period of time.6 In 2 C.J.S., supra, § 68c at 495, the rule is stated that “mere lapse of time before the consent is acted on and adoption proceedings prosecuted does not render the consent ineffective.” This case does not involve a failure or inability of DPASS, over an extended period of time, to secure an adoptive placement for a child clearly freed for that purpose by relinquishing parents. In this case, the agency’s hands have been tied by litigation.
TR is now seven years old, and JS is six years old. The record reveals that the children initially exhibited emotional and behavioral problems in their foster placements after being relinquished. Consequently, in order to prepare the children for an adoptive placement, DPASS placed them in a group foster care-treatment program for troubled children. Testimony by their supervising social worker at the hearing below indicated the children responded well to this placement. We anticipate that DPASS will be able to expeditiously arrange for an adoptive placement for these young children, provided, however, in the case of TR, that no further difficulties are encountered in freeing her for adoption.
Affirmed but remanded to the district court for modification of the order in accordance with this opinion.
THOMAS, J., dissents and files an opinion in which GOLDEN, J., joins.
GOLDEN, J., dissents and files an opinion in which THOMAS, J., joins.
. In late 1983 or early 1984, appellant’s husband was sentenced to the Wyoming State Penitentiary upon a conviction for a sexual assault not involving appellant or her children.
. More precisely, the defect in the original proceeding was the failure to provide counsel to represent the children’s best interests in the termination proceeding, as in fact DPASS had *1109been appointed as guardian ad litem for the children. The opinion in the earlier appeal, P.R., 726 P.2d 500, does not make this distinction entirely clear.
. Section 1-22-109 was amended in both 1986 and 1987. This case arose prior to these amendments.
. Section 1-22-114(a) provides:
Upon the entry of a final decree of adoption the former parent, guardian or putative father of the child shall have no right to the control or custody of the child. The adopting persons shall have all of the rights and obligations respecting the child as if they were natural parents.
. The adoption statutes of some states provide, and some courts have held, that a valid relinquishment deprives the natural parents of parental rights but that it may not always terminate certain parental obligations to the child, such as support, which may continue until the entry of a final decree of adoption. See 2 C.J.S., Adoption of Persons § 12 (1972), and Colo.Rev. Stat. § 19-5-104 (Cum.Supp.1988).
. The 1986 and 1987 amendments to § 1-22-109 did not change subsection (d).