Its not crazy unless she really has issues with hand eye and foot coordination. I would find a really cheap used clunker of a car with a manual trans and teach her on it so that if you get a 500 dollar car and she messes up the trans its not going to be to bad. You could also help her get a better used car with a manual trans that wont be an arm and leg to repair should she destroy the clutch or trans but the choice is yours. Also consider that most new cars are now automatics with sporty models being the few that have manual numbers as fewer and fewer people know how to drive one.