I thought it was the new coach who wanted her to finish hello elbow style causing her back pain?
That's how I understood it.
FWIW - When working with a new group of players, I ALWAYS ask if any of them are working with a private hitting instructor before I start offering direction. Even if I don't agree with the mechanics that the player is being taught, I know that throwing conflicting cues or instructions at them is likely to put a speed bump in their progress, and waste their parents' money. Then again, I'm not a coach with MANY years of experience, just a dad working hard to educate himself in order to provide good direction to his own DDs.