This is interesting. Did you allow the players to have gloves on at all during this drill? Any other restrictions, hands by their sides, hands can't touch the ball, etc.?One thing that worked for U12 softball was to get a couple dozen smush balls- check Amazon, they’re sponge rubber. I’d put the girls at IF/OF positions, stand on the mound, and throw pop ups. The girls had to get underneath and try to have the ball bounce off the top of their head. Made it a competiton, last one not to miss won a prize. They thought it was a blast and it helped them get the sense of “get yourself under where the ball is going to come down.” Skill of using hands came later. Didn’t work so much for balls in the gap, overhead etc but that’s intermediate/advanced skill. For the simple idea of getting your body underneath the spot where the ball is going to come down on a pop up it works better than anything else I tried.