Hello Charles Malota,
Since this girl is competitive, I would hire a professional trainer with dance experience to do a consultation which will determine the exact moves that need to be done. There may be imbalances that we are not aware of right now.
I agree that landing on two legs first is important and work your way up to one leg moves. Start low jumps, even if on the floor for now and progress to boxes and ladder training.
NAPS 2 B Fit