It could even be a separate condition, has anyone in her family had Alzheimer's?
It might be good to get an evaluation for it just in case..
If you can encourage some crafts or hobbies that are simple that might help.
Will your dad be able to take over the bills and such, or perhaps if they do them together , she will eventually let him take over that job..
Many bills can be set up to pay online automatically with credit card , then just a single payment once a month to pay off that balance.
I'd like to get my parents bills set up that way , but no go yet LOL..
all those stamps & envelopes & the fuel/time for postal workers & trucks... when you can do it online...