That’s a really good idea.
I hate to sound tinfoily, but is it even remotely possible that she was coerced into signing something while you weren’t there? Does she have a Living Will? Do you or anyone else in your family have Power of Attorney?
Find out if they are giving her morphine. If they are, ask that her pain be handled with vicodin.
Get her off the morphine. They will keep increasing it, until she dies.