Thanks for your reply. I guess as an ex baseball player I am trying to understand why you wouldn't want to utilize your hips (as baseball pitchers do). I understand the unique differences of overhand and underhand pitching however I would say at this age she has small hips (no hips, very small) and it would seem to me you would get more power if you closed the the hips or closed them slightly (45 degrees as others have mentioned)
Seems like the hips play a huge role in baseball pitching.