Children and Your Will
In most states, having a child would change your will so that the new child would get a share equal to that of any other children. However, in some states, having a child may revoke your will or result in the new child getting a larger share than the other children.
Example: Dave made a will leaving half his estate to his sister and the other half to his three children. He later had another child and did not revise his will. In some states, upon his death, his fourth child would get one quarter of his estate, his sister would get three-eighths, and the other three children would each get one-eighth.
It is best to rewrite your will at the birth of a child. However, another solution is to include the following clause after the names of your children in your will.
"...and any afterborn children living at the time of my death, in equal shares."