Betty, I'm a nurse but not an expert here. Sounds more like dementia than Alzheimers to me though.
I honestly don't think she is aware of her life passing by like you or I would be.
You've been given some wonderful advice by the others.
Check out help in your area and above all let her know how much you love her frequently.
We are all here for you. PM me anytime.
HUGS, Sue