...If I am varsity coach, I would say GO PLAY. GO GET BETTER, GO HIT GO BE A CATCHER FIRST SHORT OUTFIELD. Practice twice a day if YOU WANT TO...
No, you wouldn't. Unless, of course, you wanted your varsity team to disappear. Nearly every school district I've ever heard of will rule a player ineligible if she plays with a non-scholastic team during the scholastic season. School coaches don't make the rules. As much as I want my girls to get better on their own, I do not want any hassles from the district over eligibility, and that's only at MS level.