NAH- this is a huge physical and emotional responsibility. However, it still may be worth at least trying. Group homes can be awful. It sounds like your sister is very aware/emotionally and mentally engaged, which could make that living situation hell. But your life in no way should be dominated by hers. If it’s something you think you could manage, it may be worth a try. Why isn’t your other sister offering to help at all? Could you switch off her living situation? Not that a bunch of strangers on the internet can advise you on this. Take care of yourself first. You shouldn’t sacrifice yourself or your family for your sister. I wish you the best of luck. I know this is a really rough situation.