*639The Family Court’s determination that the mother abused Andrew B. by repeatedly subjecting him to unnecessary medical treatment, either as a result of Munchausen Syndrome by Proxy or otherwise, and derivatively neglected his sibling Lauren B., is supported by legally sufficient evidence and the preponderance of the credible evidence (see Matter of Patrick GG., 286 AD2d 540 [2001]; Matter of Suffolk County Dept, of Social Servs. [Ellen S.], 215 AD2d 395, 396 [1995]). The evidence established a history of repeated fabrication as to Andrew’s medical conditions, including her assertions for approximately one year that Andrew *640B. suffered from recurring fevers, which required his withdrawal from school for the 2005-2006 academic year. Her conduct demonstrated fundamental flaws in her understanding of the duties of parenthood, warranting a finding of derivative neglect with respect to Lauren B. (see Matter of Amber C., 38 AD3d 538 [2007]).
Further, the father’s failure to question his wife’s judgment, although he was present in the household and accompanied the mother and Andrew B. on some visits to medical professionals, justified a finding of neglect with respect to him.
The parents’ remaining contentions are without merit. Spolzino, J.P., Angiolillo, Balkin and Leventhal, JJ., concur.