My concern is how can that be done when she's comfortable where she is right now? I think she's afraid of growing up, so this situation is perfect for her, and my parents, mom especially, is happy to give her what she wants all the time. I can't see any way that she'll want to change until my parents finally break, and then I worry about irreversible damage being done to our relationship as a family.

I've already gotten in a fight about this with my mom back in March. She wanted sister to stay with me back in April and they'd pay me rent for her. I told her no for various reasons, and my mom literally flipped and said some incredibly hurtful things that I'm still trying to get over.

Change doesn't happen unless the person is put in a situation where they want it. And I worry that the path we're going down as a family is going to do more damage to the rest of us rather than encourage her to change.