When to know

Welcome. I agree with SdianeL. Even the early stages of dementia are iffy for driving. There is just too much on the line. She could kill someone or herself. It’s not worth the risk. She will never come to you and say I’ve decided I shouldn’t be driving. Many with dementia have anosognosia. This means she can’t recognize her own symptoms or limitations. It makes things so difficult. In my area there is a place the doctor can refer you to for a simulation driving evaluation. I think it’s probably more through than the dmv. But honestly if she is far enough along to have a full dementia diagnosis she probably shouldn’t be driving. If you think this will be a fight ( it usually is), you might try telling her the car is in need of repair and take it to someone else’s house, she could “lose” her keys, you could do something to disable the car. I know these things seem deceitful and dishonest, but if you are upfront with her and tell her she is not capable, it probably won’t go well (but you know her best).

I would contact your local commission on aging. They might have some kind of driving service for the elderly. It might just be a good resource. Does your town have any public transportation? I would not let her use public transportation alone though. Are you able to go with her?