FiveFrameSwing
Banned
One thing I see right away that is common in most young players I have worked with is that her back elbow is "sliding" in front of the hands. I would start here and correct this first by having her feel the connection between the rear elbow and her backside ribcage. The hands should always remain in front of the rear elbow.
You can correct this by taking dry swings to launch (knob of bat pointing to pitcher), no follow through, and video the swings so she can watch the connection. It will take a few weeks or even months to correct the muscle memory, but its a must.
The hands remain in front of the rear elbow here ... but this isn't the swing many of us are after.
The hands are not always in front of the rear elbow here ... and this is more in tune with the swing that many of us are after.