If its her apartment then its time for you and Dad to find a place of your own. Dad may have an easier time getting help alone. Try Social Services to see if housing can be found for him or you and him.
If u have trailer parks in ur area, check them out for renting.
It is technically her apt though the 3 of us share expenses. She refuses to move. I am so afraid of what I guess will happen and that is to somehow move to a 1 bedroom ground floor dwelling. Not money or support to do so. But, I have to get us out of this abusive situation because when she has 1 of her frequent bi polar rages it is unbearable. Guess I am feeling scared and sorry for myself right now. Thank you for responding. I know I am not alone.
That is very sad. Here is a somewhat different situation where your stress is not brought on with your aging father but your sister. We don't know the circumstances of why she is living with you but she certainly seems very ungrateful over all and is clearly not bringing anything positive to your living environment. I agree with others in that she does not deserve to be in a home where care would be helpful and is only seemingly a negative influence. Hope you solve this situation and perhaps could explain to us why she is in your home.
If u have trailer parks in ur area, check them out for renting.
How long has it been since you and Dad moved in? Where is he on ADLs? How much household disruption has occurred?
If it's sister's, then unfortunately you guys should go to somewhere where she won't be.