The deeper question is why is she leaning over and getting her weight out on the front foot? She depends upon arm circle/wrist snap for speed, the fact that she never really opens up and that her shoulders are much to closed coming into release are indicators of this. The palm up follow through is also a sign. This is typically how all pitchers start out. She leans over and gets on her front foot because she has subconsciously learned from experience that this will help her keep the ball down. Rick is right, if you want her to straighten up just get her to throw it high, the higher you let her throw it the more she can straighten up. But she is still going to have learn to throw it fast and keep it down and this is very difficult with the arm circle/wrist snap motion. She needs to learn the correct arm action to get over this problem. Take her out and teach her to throw sidearm or learn to skip rocks on a pond. Once she masters this then get her to lower her release point and move gradually into the slingshot motion. From there ease into windmill. Leaning over with the weight on the front foot is a symptom of her present arm action/release, without changing this she will continue to lean over or she will struggle with high pitches every time she tries to throw hard.