There are many people who suffer from every illness imaginable yet they don’t treat their family poorly. It’s not a rule that sick people should be allowed to mistreat others. Of course if you are ok with mistreatment, it’s fine but it’s not something you simply must endure because she is sick. She isn’t the only sick person on the planet. And if her illness isn’t the kind that she is unable to control what comes out of her mouth, then she surely is able to control what she says and what she does. Having said that of course if you want to endure all that abuse, then who are we to say otherwise.