How do I deal with a sister that doesn't agree with the care I'm giving my Alzheimer's parent?

How do you deal with your sister? Gently, if at all possible. She is probably sincere (if mistaken) in her ideas of what would be good for Mom. But you have been entrusted to make decisions. I am so glad you have found a place where Mom is content!

We had a similar problem when mom moved to Assisted Living. Two of three children had their hair on end, saying we were rushing things, it was too soon. They went all to pieces when we rented out the apartment and things had to be moved out. YOU are doing the RIGHT things. They can't accept reality right now, but hopefully they will. It takes time. Your mother made the right choice picking you as POA, you are level headed.