New York Consolidated Laws, Estates, Powers and Trusts Law - EPT § 6-5.7 Posthumous children

(a) Where a future estate is limited to children, distributees, heirs or issue, posthumous children are entitled to take in the same manner as if living at the death of their ancestors.

(b) A future estate conditioned upon the death of a person without children, distributees, heirs or issue is defeated by the birth of a child conceived before but born alive after the death of such person.