What might work is a little cheat sheet for parents.
Maybe a top ten things that they many get wrong.
1. I know the runner scored before the out at first, but is still doesn't count.
2. Not every fly ball in the infield invokes the infield fly rule.
Any help on the next 8
3. Foul balls: how to recognize them, and refrain from the desire to inform the batter-runner.
4. Pitchers can have sunglasses, multi-color gloves, and wrist bands.