Accounts with a named beneficiary are not subject to the will.  Those accounts pass to the named beneficiary immediately upon death no matter what the will or the laws of intestacy (the law that would give the other child any right to the estate) say.You should consult a probate attorney where your father died about the suspected child.  The executor is not responsible for splitting the estate assets with someone who is not mentioned in the will.  However, if you have good reason to believe your father had another child, the executor may be required to give that person notice of the estate. The suspected child may have a right to contest the will. Whether he or she would win a will contest is doubtful.  A will contest would also cost this suspected child a lot of money.  Usually, in such instances, the other child does nothing, especially if the estate is small.I hope this helps.