N.Y. EPT. LAW § 5-3.2 : NY Code - Section 5-3.2: Revocatory effect of birth of child after execution of will

(a) Whenever a testator has a child born after the execution of a last
  will,  and  dies  leaving  the  after-born  child  unprovided for by any
  settlement, and neither provided for nor in any  way  mentioned  in  the
  will,  every  such  child  shall  succeed to a portion of the testator's
  estate as herein provided:
    (1) If the testator has one or more children living when  he  executes
  his last will, and:
    (A)  No  provision  is  made therein for any such child, an after-born
  child is not entitled to share in the testator's estate.
    (B) Provision is made therein for one or more  of  such  children,  an
  after-born  child  is  entitled  to  share  in the testator's estate, as
  follows:
    (i) The portion of the testator's estate in which the after-born child
  may share is limited to the disposition made to children under the will.
    (ii) The after-born child shall receive such share of  the  testator's
  estate,  as  limited in subclause (i), as he would have received had the
  testator included all after-born children with the  children  upon  whom
  benefits  were conferred under the will, and given an equal share of the
  estate to each such child.
    (iii) If it appears from the will that the intention of  the  testator
  was  to  make a limited provision which specifically applied only to the
  testator's children living at  the  time  the  will  was  executed,  the
  after-born  child  succeeds  to the portion of such testator's estate as
  would have passed to such child had the testator died intestate.
    (iv) To the extent that it is feasible, the interest of the after-born
  child in the testator's estate shall be of the same  character,  whether
  an  equitable  or legal life estate or in fee, as the interest which the
  testator conferred upon his children under the will.
    (2) If the testator has no child living  when  he  executes  his  last
  will,  the  after-born  child succeeds to the portion of such testator's
  estate as would  have  passed  to  such  child  had  the  testator  died
  intestate.
    (b)  The  term  "after-born  child" shall mean a child of the testator
  born during the testator's lifetime or in gestation at the time  of  the
  testator's  death  and  born thereafter. For purposes of this section, a
  non-marital child, born after the execution of  a  last  will  shall  be
  considered  an  after-born child of his or her father where paternity is
  established pursuant to section 4-1.2 of this chapter.
    (c) The after-born child may  recover  the  share  of  the  testator's
  estate  to  which such child is entitled, either from the other children
  under subparagraph (a) (1) (B) or the testamentary  beneficiaries  under
  subparagraph  (a)  (2),  ratably,  out  of  the  portions of such estate
  passing to such persons under the will. In abating the interests of such
  beneficiaries, the character of the testamentary  plan  adopted  by  the
  testator shall be preserved to the maximum extent possible.