I am sorry to hear about your mother, and regarding siblings I don't know why that everyone can't come together (not just speaking of your situation) and help each other. I have the same thing my Dad died in July and my mom has been in the hospital 8 times that I knew nothing about because she didn't want to worry me. My brother brings her over and she is a skelaton (sp) with skin. She was staying with me and ended up in the hospital but I inform them of how she is doing because I think it is the right thing to do.
As far as your situation you have to do what is right for you.