C.S.
I have boys in baseball, and if I remember correctly, to get the proper length measure the length from the hip down, and that should give you the correct measurement for a bat. It may be different for girls, I don't know for sure, but someone at a sporting good store should be able to help you pick one out correctly as well. Is it mandatory for all players to have their own bat? Sometimes coaches have several for use, if that's the case, have her try out a few and see which suits her best, the coach should also be able to help to :) Have Fun and Good Luck!