Celia,
I'm so sorry for what you and your mom are going through. It must be very difficult. I can hear it in your post that you are so distraught. I would be too. I know that you got a lot of responses about nanny cams, but I was wondering if it is possible to mover her in with you since you are home already. If she is very ill it probably won't matter to her where she is, but who she is with. Then you could still get an aide to help you out, but you would be right there to monitor, and then you wouldn't miss a moment with your best friend.
I wish I could reach right through the screen and give you a friendly squeeze! Trust your instincts..we daughters are really tuned in to our mothers and their needs, aren't we? Sounds like your mom is very lucky to have such a doting daughter. Hope my daughters feel that way about me when they are grown. I'll be praying for you.
D.