Is your mother alert and oriented? Is she capable of making her own decisions. If driving puts her or others in danger disable her car. Remove her distributor cap. take her keys. you are looking for someone else to do a job you are responsible for. Yes, she will be mad at you. I had a elderly man as a patient when I was a visiting nurse, The therapists everyone told his daughter he was unsafe to drive. She wouldn’t take responsibility to stop his driving. He drove his cadilac through the back of the garage, the garage collapsed on top of him. Luckily he wasn’t killed. I see it as if you have a toddler and you let him ride his bike in the road, and he is injured, you are responsible. It s the same thing when we let our parents drive. When they clearly are unsafe and unable.