what to do??

At 10 I doubt she will get called for an IP especially if it is only happening 25% of the time. I think at that age they'll cut her some slack.... heck even in the upper age brackets I do not see blatant illegal pitches called very often.

My DD had a similar issue when she first transitioned from step to L&D. Here is what we did (many off this list were suggested by the nice people of this forum):

1. Video her and show her when she becomes illegal.
2. Explain the rule to her why that motion is illegal.
3. Show her images of Pitchers doing it the correct way.
4. Setup a pitching area in your basement or garage with a pitchers plate. Put a piece of 8.5 x 11 printer paper under her pivot foot.
5. Without a ball have her simulate a pitch telling her to focus on dragging the sheet of paper.
6. When she starts to get it, tell her to try an drag the sheet of paper without tearing a whole in it.
7. Giver her a ball and throw into a net from a short distance w/o worrying about speed and location.
8. Alternate a few w/o the ball then one with the ball.
Rinse and Repeat....

We used to carry several sheets of paper with us to pitching practice to reinforce the proper drag.

Many of us have been in your position. You have plenty of time to fix this problem before April, don't sweat it. I really question the PC suggesting completely changing the pitching style to fix a minor problem... what happens later down the road when she struggles with control or speed, which she will... they all do? Will this coach want to change styles again?

Fix the problem, don't change styles. This issue is going to have to be addressed at some point, why not fix it now?

Is he switching her to step style or just shortening her stride while she works on syncing up her motion? I could understand the second and have seen it done many times.

Thanks for all your replies and great ideas. I will post some video later this week. Knightsb- I will try what you did and let you know how it works out. She did pitch on a pitching mat if that made a difference I am unsure. My suspicion, as someone suggested, is that she leaps up and not out, but I am a novice. Thanks again for the great ideas.

Many report that pitching on a smooth floor leads to some leaping.

Video would really help. I like using paper/rag/rope/cardboard if all else seems to be in good shape. As mentioned by others, if there is another mechanical or timing issue resulting in leaping as the symptom, the video will help identify the cause.

In my years, what causes leaping is very simple. If the pitcher starts their push from the rubb and they are standing straight up or nearly straight up, they will push off at a very upwards angle.

If the pitcher's entire body is on a good forward lean and the center of her body weight is well ahead of the rubber, she has no choice but to push off forward and next to no upwards energy spent.

Start on a good forward lean and stop on a backward lean with a slight bend in the stride knee.