Interesting how the kid's pitching coach, who was apparently an effective pitcher and is apparently teaching what the vast majority of top pitchers do, and generating positive results, can be so thoroughly second-guessed. It parallels the hitting threads where the "mechanics" of top college hitters are picked apart as they don't conform so someone's personal vision of what's ideal.
Exploring whether your DD CAN pitch is a worthwhile exercise for a 9 yo. However, the vast majority of prospective 9 yo pitchers won't get anywhere near the circle in even a varsity HS game. Don't over-analyze, and make sure the effort expended in learning how to pitch doesn't displace the hitting and fielding fundamentals that will keep her in the game should the pitching experiment fail.
Exploring whether your DD CAN pitch is a worthwhile exercise for a 9 yo. However, the vast majority of prospective 9 yo pitchers won't get anywhere near the circle in even a varsity HS game. Don't over-analyze, and make sure the effort expended in learning how to pitch doesn't displace the hitting and fielding fundamentals that will keep her in the game should the pitching experiment fail.