Legal Question in Family Law in Illinois

That is correct. In order to put the baby's father's name on the birth certificate, he must sign a "Voluntary Acknowledgment of Paternity". This form is available from the hospital where the child was born. If your daughter is certain that her husband is not the biological father of the child, she should leave the father's name blank. Her husband will still be the legal father of the child since they are still married but this can be resolved at the time of any divorce. Also the biological father is not absolved of future responsibilities just because he now refuses to sign the voluntary acknowledgment and his name can later be added to the birth certificate.