This might sound simplistic but ensure that she knows how to jump up in the air. Straight up by bending knees, bending ankles, and pushing up with balls of her feet. Swing her arms. Whatever it takes to get her leaping up. Most girls don't know how to jump and yet it seems to be a no teach with boys. Have her pretend she is jumping across a puddle of water or something. Don't be surprised if you have to keep reminding her to bend her ankles. Have her compare jumping straight with trying to jump and not having her foot in line/pre-turning foot. If she is pretending to jump over something, she won't pre-turn her foot prior to pushing off. A couple weeks focusing on that straight drive and I bet you are pleasantly surprised as it is incorporated into her leap. And when her leap looks weird (maybe it's just my dd ) remind her once again to bend her knees and ankles.