how to fix timing too early on a player who's bat speed has increased a lot

[Towny9]

It's fairly simple. Full EXTENSION after contact. DD had a habit as many younger kids do. They fold their arms around their and hit their back. They seen some older kid doing it and they think that's what to do. I had her over exaggerate the swing which leads to more torque, which forces more rotation. She would let go of the bat with her right hand as her left hand kept going.

No extension here. Early extension, or when kids over-emphasize extension, makes many kids disconnect early and get long - making the inside pitch hard to hit.