"What's yours is mine, what's mine is mine"

My son-in-law bought a house with his girlfriend. Her name is on the deed and the mortgage. His name appears nowhere on these documents. They have since seperated. She has hired a lawyer to get him to pay half of everything. He pays child support for his son who lives below him. He also has a daughter who will be moving in with him soon.

Is he legally bound to pay anything for a house he is not living in? A truck was also purchased in her name and she wants him to pay for that also. Does she have a case? Thank you.....

Unless a court orders him to pay for some reason he is not obliged. He has never agreed to pay for the home in writing based on what you say here.