How old? Some good things happening. May want to visit the sticky threads in this forum to get some IR going. Check out I/R in the Classroom. Looks like she is off to a good start.
Some completely non-technical advice - have her take a breath / pause between pitches. Not sure if it was rushing for the video but she didn't even seem to get her feet settled before she began her next pitch. Better to throw 30 controlled pitches in a practice session then 60 rushed ones. It's a bad habit I had to break my own daughter of in practice and in games.
Read the Drive Mechanics thread also. If she drove out with her knee instead of reaching with the foot then she would be much more explosive. She should strive to get her shoulder line a little more open also so she throws across her body. She will get there just take it slow and enjoy it!