765 ILCS 5/14

When an estate hath been, or shall be, by any conveyance limited in remainder to the son or daughter, or to the use of the son or daughter of any person to be begotten, such son or daughter, born after the decease of his or her father, shall take the estate in the same manner as if he or she had been born in the life time of the father, although no estate shall have been conveyed to support the contingent remainder after his death.