I have to wonder @Love_Hope if its not a grudge towards you, its quite possibly the schizophrenia causing the disconnect between you and your sister. If its the schizophrenia causing her feelings towards you, you will have to give her a lot more time on meds and in therapy before you can be the person to help her.
My husband takes all of my son’s negative feelings toward him personally. He’s wrong and trying to convince him otherwise is like talking to a rock. At least a rock I would have a chance at moving off a set position.
Oh, I am so sorry to hear that she cannot accept your help, as you wish she would. My guess is that in her mind’s eye, somehow you (with your good wishes) are not the person she sees when she looks at you. Somehow she sees someone she doesn’t want to live with. In her mind, you are not the best option for her. It is probably the schizophrenia clouding her, with delusions that she can’t overcome.
@hope is correct, if she has the inability to decide to go with you, you must try to understand that she believes herself, at least for now. She might need a LOT more time on meds and perhaps therapy before she can allow herself to be helped by you.
Even in my daughter’s deepest psychosis, or on the meds that didn’t work well for her, she always eventually came back home to me instead of other possible places to live. I am lucky that she wanted to be with me and let me help her.
Your sister may go back to brother’s. At this point, perhaps the key is to help her stay on her meds somehow. If it’s been 4 years since she has been able to think/talk coherently, then a few weeks may be too early for major changes in living to feel comfortable to her.