@ilovechili I'm under the impression that her son also has her last name, though not sure why. In Indiana, you have to sign a paternity affidavit for the child to take the father's last name if the parents are not married. It's not really a complicated process... my husband and I were not married when our son was born, only engaged, and they basically just have a legal representative who works for the hospital come to the room with a 1-page form that both parents have to sign. By the time the mom and child are released from the hospital, the child's last name will be legally changed to the father's name. I'm pretty sure, based on pics I've seen on SM, that she gave birth at the same hospital I did, so the process would be exactly the same. Although we were aware of the process prior to birth and were very conscientious about asking about it, so it's entirely possible she had no idea and was just told "sorry, you're not married, it's the law, child has to have the same last name as the mom"
ETA: It's also entirely possible LH was not present at either births, which would explain him not signing an affidavit.