My brother wants to sell my Mother's contents of her home while she is in the nursing home. Can I remove her things from her house?

My mother is in a nursing home - I have Medical Power of Attorney, but not durable Power of Attorney - my Mother and I both agreed it should be the family attorney. Mom is still very much alive, but suffers from some demintia, congestive heart failure, incontinence and a traumatic brain injury from a car accident many years ago. She is also legally blind. She will never be going home again. I have not done anything with her house, I guess hoping for a miracle that she might go home someday, but the Doctors say that will never happen. She has many valuables including antiques in a very large victorian home. Just last week, the police were called to her home as the neighbor saw someone prowling around the house, looking in the windows etc. Even though the house is locked up and the windows are locked and secured, it's just a matter of time before someone breaks in. She lives in a rather small town and was well known before she went to the Home. There is me and my brother only, but my brother has not been in her life for years now so I am the only one who takes care of her. I'll note she is private pay in the nursing home and will be for many years so finances aren't an issue.
I am proceeding with removing all her contents from the house with the intent to hold an auction and sell some of the contents and store others until she passes. My question is, do I have to go through her DPOA for approval before I do this? Since I am her daughter and she is still alive, do I have the right to do this so 1) isn't the victim of a crime and lose valuable property; 2) I plan to put it in an account for when she does; 3) her DPOA has said we need to sell the house eventually anyway and I can't do that with the contents in it.
The main reason I don't want to get him involved is because I know he will want to sell everything and I'm not ready for that to happen. Any information would be welcome!!!