My daughter is 14 years old can she give up all rights of her unborn child to the father who is 16 years of age the mother of the 16 year old came to my house today and my daughter singed the papers is this legal

If minors sign contracts they are voidable. I think it should be the same in the case of giving up rights.
IF you want to dispute this you should do it ASAP rather than letting it go for any length of time.