I have a tendency to dump my first serve into the net. Then I changed my trophy position to wind my shoulder more. This affected my timing and contact point and had the unintended consequence of fixing my first serve issue.
I suggest changing your forehand takeback a little...maybe one that...
If she is a girl and I am teaching her WTA forehand, I would ask her the opposite question. Whatever it takes to motivate them. Ask any 6 year olds if they like the opposite sex, they will say ewww.
The thing is ... would you take the chance that they will naturally move to ATP or would you play an active role and teach them the ATP. Personally I would take the latter approach. Over coming the muscle memory is not an easy task. I prefer teaching the right strokes and having the right grips...