Your DD is doing alot of things well. I had a student that was an up and coming pitcher that tore a ligament if my memory is correct in her throwing shoulder. She was a dominant pitcher in her MS at 12 yrs. old in her school district. She had 109 strikeouts in the 7th grade. (She never said how many walks she had.) She was asked by a TB to come join their team and at the first practice, the team PC told her to take a more aggresive backswing and after a couple of pitchs she injured her shoulder. Went thru 4 mos. of PT. After the Dr. cleared her to start pitching again, we started back and she was afraid to ever throw the ball hard again because she didn't want to experience the pain she felt and all the rehab she had to go through and eventually decided to quit pitching.
I know alot of Elite Pitchers have an aggressive backswing(Amanda Scarborough) but are quite older and their shoulders are well conditioned over the years of pitching and know their limits. Your DD swings back hard enough that it is getting the arm behind her head. It also starts her arm out of the pitching plane but she recovers well. I would also have her stride more down the powerline.
Thank you. Her backswing has always made me cringe a little. It's something she always did since she started. She's toned down the high pump at the start of her pitch maybe I can get her to do the same on the backswing.
She needs to stop jumping to the right though. It's quite a noticeable jump and you want everything to be going towards the strike zone, not just to the right of the strike zone.
She looks very good, and as others have mentioned, she is doing a lot right.
The jumping to the right has a lot to do with her motion moving to the left from the start. Notice her pre-motion. She doesn't really load her legs, and then gives it up whatever load she does have by twisting her foot sideways before she pushes off. This makes her push off towards first base, and it's all she can do to keep from falling over if she doesn't lean towards third base. Fix that foot, and you'll fix a lot of the issues later in the chain. She'll also be able to use load up her bottom half to get a lot more drive and power.