DECISION ORDER
ORDERED that the judgment is affirmed insofar as appealed from, with costs.
The Supreme Court's determination must be "accorded great deference on appeal, since it had the opportunity to assess the witnesses' demeanor and credibility" (Miller v. Pipia, 297 A.D.2d 362, 364; see Eschbach v. Eschbach, 56 N.Y.2d 167, 173). We are satisfied that the Supreme Court's award of custody of the parties' two younger children was in the children's best interests (see Eschbach v. Eschbach, supra at 171-173). The defendant's conduct in alienating the children from their father is an act so inconsistent with the best interests of the children (see Barbato v. Barbato, 264 A.D.2d 792; Young v. Young, 212 A.D.2d 114, 122) that it cannot be said that the Supreme Court's determination lacked a sound and substantial basis (see Eschbach v. Eschbach, supra; Miller v. Pipia, supra).
While the two younger children were closely bonded to the defendant and expressed a clear and consistent desire to live with her, their preference is not determinative, given their young age, lack of maturity, and the fact that they were so strongly influenced by the negative attitudes of the defendant and their older siblings (see Eschbach v. Eschbach, supra at 173; Muller v. Muller, 221 A.D.2d 635, 636-637; Young v. Young, supra at 123).
The defendant's contention that the parties' settlement agreement, as modified, must be vacated on grounds of unconscionability, duress, and fraud, is not properly before this court, since the record in this case discloses that the defendant mother, in open court on February 18, 2000, voluntarily, knowingly, and intelligently stipulated to waive her right to appeal the order dated February 3, 2000, denying her motion to vacate the settlement agreeement in exchange for an additional payment of $45,000 from the plaintiff father (see Matter of Department of Social Servs. v. Herbert R., 213 A.D.2d 636). Having failed to show any ground upon which to set aside her waiver (see Hallock v. State of New York, 64 N.Y.2d 224, 230; Bruckstein v. Bruckstein, 271 A.D.2d 389, 390), the defendant cannot now contest the denial of her motion to vacate the settlement agreement.
The defendant's remaining contentions are without merit.
SMITH, J.P., McGINITY, TOWNES and COZIER, JJ., concur.