Would it get through to her if you told her about the risks involved for others? It sounds brutal but what if she killed a child? Or hit a car with a young family inside? You and everyone else involved are absolutely correct in your stances. They say, “oh I’d be really careful.” What about reaction time? I’m edging towards having this conversation with my MIL and preparing myself. They fear a loss of their independence, but there are other ways to have independence. Plus the half price taxi is really cool!