Her father, Charlie's grandfather, lives with her. Cutting her off would require cutting him off as well. He enables her drinking. He's an excuse for her drinking, because taking care of him is a stressful thing for her. Charlie wants to get his grandpa down here, to take care of him, or hire someone to take care of him up there.
Grandpa refuses both.
He has money. He just refuses. So what can Charlie do. What do I do, he says. To him alone.