Can I disown my children in my will?

Your children will have a legal right to a portion of your estate if you die without a will stating otherwise. You need a will specifying who will inherit your estate.

Yes. A will allows you to pick and choose who gets what out of your estate. But you have to specifically dole out who will get what. A will that just says "my estate to anyone but my children" usually isn't held as being valid.

Did you sign their birth certificates