Questions regarding mother's home and selling it

[wvuftbl1]

What is the name of your state (only U.S. law)? West Virginia
My mother was diagnosed with Alzheimer's. She is still hanging in there. We are in the process of doing the whole power of attorney thing. Our family plan is that my sister and her family will move in to take care of our mom. I have a couple of questions regarding this.
Our parents divorced 24 years ago, but both of their names are on the deed. We initially thought that they would just sign the house over to my sister so that it is now their's because they are taking care of her. They will also be selling their home to use that money to make much needed repairs.
We need to know what the timeline is in the event that our mother needs to go into a nursing home in the future that they can come take the house back. Does the fact that our father's name is still on the deed play a role? Also, would it make a difference if the house is just signed over to them as opposed to it being sold?
Finally, how many doctor's should declare her competent to prevent any future arguments on her state of mind? She is fully aware of what is going on, we just want to cover our bases where our sister-in-law is concerned.