Chris won't have the house or mortgage when Barb dies. Thanks to Barb's greed and insatiable compulsion to acquire worthless Goodwill shit, she pretty much assured that Chris will be homeless shortly after she croaks. She got their mortgage changed to a reverse mortgage sometime after Bob passed away. So she gets to have more money every month to waste on worthless trinkets and used, out of style clothes, the lending company or bank who holds their mortgage gets the house, and Chris gets booted to the street to fend for himself. Barb guaranteed that her son will never have a chance to continue living in the house he (mostly) grew up in and spent most of his life in. He'll only be able to take what he can fit into his car, if he's lucky to have a car that's running. Maybe this is Barb's way of paying Chris back for putting up with his childish nonsense, the arrests and legal issues, and caring for him up until her sundown years? It is pretty cruel.