How do I get her out of my house?

Get help! Sometimes it comes from outside sources, like the other responses said. The longer it goes, the worse it gets. Reach out to others resources.

I am assuming here that she didn't assign you POA? So you really have no power to place her. I suggest you call Office of Aging. Let them evaluate her. Explain that you have no legal standing. That she is to the point she needs care that you are not capable of giving. Hopefully they will see she gets evaluated and some tests run. But make it plain, she cannot come back to ur home. The state can get guardianship and place her in LTC.

Please come back and tell us how things work out.

Contact Social Services or your local agency to come in for an evaluation of her dementia and her actions of being a danger to herself and others. I know you're not married, but it can ethically get the ball rolling for her to be cared for, either with another family member or in a nursing home.

Mickeyl, I see from your profile your sig other has dementia. You need to keep telling yourself that your sig other's brain is broken. How long have the two of you been together?

Sadly your sig other will not be able to live on her own. Does she have any immediate relatives that can help you? Can she budget to live in Assisted Living/Memory Care? If not, check to see if she could qualify for Medicaid [which is different from Medicare] because if her memory is difficult, Medicaid could check to see if she would be qualified to live in a nursing home.

I can understand your frustration, but what if the roles were reversed? Just food for thought. You probably would want her or someone there to help care for you.