Can my grandfather be legally made to stay with my sister?
This may be one of those times where collective knowledge of the masses doesn’t point to the truth.
If your grandfather is mentally competent—that is, able to comprehend the content and meaning of documents and such—then no one has legal authority to control where he should live or stay, unless he has signed a power of attorney giving that person immediate power to do so. It doesn’t sound as if that’s your case.
Your best option may be to hold a big family meeting focusing on your grandfather’s best interests. If there is one person best suited to providing for his care, urge your grandfather to complete a durable power of attorney appointing that person as his agent.
If the consensus is that your grandfather is not able to care for himself and is likely to bolt from the custody of his caregiver, consider securing an adult guardianship or conservatorship. Such an arrangement would not require your grandfather’s consent, but would require a court proceeding. If this option beckons, find out more from the local probate court by searching “probate” and the name of the county in which your grandfather currently lives.
What a difficult situation. Our parents (I have 3 siblings) are 90 years old, and 2.5 years ago, we had to have a family meeting to get them to move to an 'independent' living facility. There was one sibling out of the 3 that was in a bit of denial about their abilities, but he agreed to be in the meeting, and to support the rest of us in our request. We have had just a couple such meetings, and boy is it helpful to be able to speak with our parents with a unified voice.
Our parents have since moved into Assisted living in the same community, and it was a bit of a struggle (both with dementia), but they are pretty happy now. My sister and I are now co-trustees on Mom/Dad's trust, and we both have Power of Attorney, both for Healthcare and for Financial purposes.