When should we stop letting my mom drive?

Your brother doesn't want your mother driving again, okay. Why not?

With respect to him and his stress levels, you and your brother don't "let" your mother drive. She drives under licence from the government, not from you; and if her doctor, her insurer and the relevant authorities say it's fine, then it's her decision.

That's not to say that retiring with her record intact might not be a better decision than waiting until there's a problem, of course. Does she have access to alternative forms of transport?

whatitis, blood pressure that is under control shouldn't stop a person from driving, heavens there are even 25 year olds that have such a condition.

As to the heart issue, did your Mom have a heart attack? I remember when my Dad did when he was in his late 80's, the doctor had him stop driving for a few months. After that Dad was allowed by his doctor to drive again.

What eventually stopped both my parents from driving was lack of good vision and physical issues, such as putting on the brake .

If your Mom has always been a safe driver, let her try her hand at driving again. But short trips until she gets use to being on the road, again.

Here in Australia people over 80 have to be tested before licence is renewed. Do you have similar?

Why does your brother not want her to drive?

Did her doctor restrict her when she had her issue and has now released her?

If she wants to assure brother that she is fine, then she could look into a refresher course. Maybe her doctor would order her some PT or OT to build up her strength.

Why is brother living with her? Is that something she wants?

I’m afraid I have more questions than answers.

Go for a drive with your mom. If she doesn’t have any cognitive issues and her reaction times are ok, she is probably safe to drive. She can also find a “55 Alive” course in her area which I believe is sponsored by AARP and is a mini driving course for senior drivers. If you notice that she has poor reaction times to red or green lights, has trouble getting into or out of parking spaces or has problems handling other drivers on the road, then you need to have a conversation with her about driving.