so ban her . This is the problem loads of people have. They think just because they've got PERMISSION to drive, it means they can push everyone else out the way- even those that were there for hundreds of years before. If you took her car away, i bet she wouldnt come up behind you on foot and shout I hate horses ! because she would know she'd get kicked in the face and is vulnerable. Cars make people like this feel superior and smug, when they arent at all. Take her licence away, horses cyclists and pedestrians all have a right to the road, cars, motorbikes, lorries, buses- all need permission that can be taken away.
Do Mercedes make tractors?