For context, I'm the granddaughter of the elderly woman in question.
My mother and I live with her, and we need her house (long story involving divorce and a lot of other setbacks, including my mom having to quit her job to take care of my grandmother). We actually pay all the bills but she doesn't believe that, since she thinks her husband, who has been dead for several years, "took care of all of that" before he died. Her name is still on the house and everything.
Today, my grandmother, who likely has some form of dementia (she's also Japanese and does not speak English well/cannot hear well, which seems to make people reluctant to diagnose her with dementia) and who has historically been verbally abusive escalated to attempted physical violence. She tried repeatedly to hit her with a backscratcher while my mother was trying to help her off of her wheelchair onto the couch.
She's threatening to make every second my mother has with her hell, and has been telling me that I'm useless/never do anything for her. This is worse than it's ever been before. What can we do? She has had C. diff and almost had her kidneys fail, so we're worried about the cost of finding a group home for her especially with the history of C. diff - and she probably won't want to go anyway. She has repeatedly stated her intentions to "die in this house".
I just don't know what to do and am worried any action would somehow be seen as elder abuse, even though she's the one abusing my mom. Any suggestions or thoughts would be really welcome.