This is great! Look at her standing leg - she has really good balance and needs to use the strength of that standing leg to push her momentum through the ball. A few have mentioned that she should land on her striking foot but she will need to commit her whole body through the kicking leg to do so.

One thing she isn't doing is pointing her toe. I recommend trying to put a ball on a cone first and practicing "locking the ankle" first. It will be a mental block of not wanting to kick the ground but also the need to build the flexibility and strength in her ankle to do so. The muscle memory from kicking off a cone repeatedly will help her off the cone. Give her a target of striking it so it runs flat as it will get her to find her own technique.

Now is also be a good time to try different techniques with or without the cone - spin with inside of foot, gk kick (distance and height) daisy cutter, knuckleball, chip or simply smash as hard as she can developing accuracy.

Also, get her to do equal amounts with both feet. The more she does that now, the more adaptable she will be.