She's 12u. 2001 or 2000 birth year? I'm curious how fast she was pitching in the video (looks like she's throwing pretty hard). I have 3 pretty solid pitchers, most around 5'1 or 5'2. The fastest one is topping out around 52, while the others are still around 48. I have a fourth who is at...
By the way, if you right-click the first two pics I posted and open in new tab, and then flip back and forth between them you can see what I mean with the shoulder.
The first thing I noticed (I snagged the video and dropped it into my video analyzer for slow motion) - is that even though her hips are still open at release, she's forcing her shoulder closed before the ball is released. She must be a pretty strong girl because that's all upper-body strength...