Friends and relatives of people with bipolar disorder: Should their 'bad' behaviour be accepted or challenged?

This is an awful situation. I am sorry for your loss first and foremost. I have a close friend who battles depression and has almost her whole life. She uses it as an excuse sometimes for bad behavior. I challenge her on it to a certain degree. If she is in a mood and wants to cranky she can but she can not put it on me, she can not ruin my time. If she needs help I am there, but a chemical imbalance does not justify being rude. It is your sisters choice to not take the medicine, but it is not ok for her to let the side effects of that fall on you. You should try talking to her about the the house, just explain she is welcome any time but you need some privacy and expect a phone call first. Unfortunately due to the bipolar you are the one always making the effort. Maybe your brothers can help? i am really sorry this sounds like a hard situation, good luck!