My mom isn't getting better after 4 months. She is still being ugly with her care givers and ungrateful for the safe home she lives at. Now it's back to getting her evaluated and adjust her meds. I'm afraid she is going to be kicked out. And then what?
Also, I would not be expecting a person with dementia to be exhibiting grateful and cordial behavior. Caretakers of dementia patient know and accept this. If she needs a higher level of care, then, that's what she needs. I would describe that as moving her to a higher level of care and not "kicked out." Once, the patient is moved to a facility where the higher level of care can be provided, hopefully, it will make a difference in her life for the better. Of course, I would seek the doctor's guidance in making her as comfortable as possible.
It's time for you to look into the next phase of her living requirements, and not Wait until she is completely out of money, and in crisis mode, to find her safe, comfortable and suitable housing, and I definitely don't recommend that you bring her to live in your home, as it already sounds like you have resentments building, which often happens, when you are unprepared for their continuing decline, I know as this is happening to me, so no judgements from me!
Hopefully you have Financial and Medical POA, so that you can make appropriate decisions on her behalf, so that you can work with your counties Social services, and come up with a viable solution for her care! Good luck!
I noticed on your profile that your Mom has Alzheimer's/Dementia... makes me wonder if she would even know the siblings current whereabouts.