TSC,
I'm glad to be of help. I can't imagine twirling with one that would meet those other measurements (neck to end of middle finger)! I would have had continuous bruises! You *can* do it in a pinch, but it looks really awkward. I remember a particular situation at a state game when I was thrown another person's baton. I thought I might as well join in with the flags!
At the risk of going on too much, I will throw in another suggestion for the purposes of her success in try-outs. Depending on her school, the majorettes may or may not use tape as a marking tool on their batons. If they do, she has probably seen it and knows how to do it. If the don't, she SHOULD use it for practicing and consider keeping it for try-outs. My alma mater used some expensive sparkly tape in our school colors for show. We would either wind it continuously around the baton or use it as described below. Either way, it helps with the grip and what I will describe as knowing where you are in the middle of a twirl. If you toss and catch it a little off-center, you can immediately compensate for that.
For her practice baton, just use masking tape. You'll want to wrap it in three places. Start by wrapping the EXACT very middle of the baton. You don't want to "spread" the tape: you only want a marker that is exactly the width of the tape itself. Just wrap it layer over layer, right in the middle. About two layers (wrap arounds) is perfect, although some prefer three. Go with what feels right to her. Next, do the same on the left and right of the middle, approximately 4 fingers or 1 hand's length away. Those two should be inside (NOT over) the little indentions that are on both sides of the baton. Have her try this for a bit and get used to it, and then see what she thinks. If she doesn't like it, just take it off. My bet, though, is that she'll find it much easier to grasp, center the twirl, and judge her 'balance' overall. The tape is also especially helpful with the hand-eye coordination when one is trying to catch a toss. Ever tried catching a baton after tossing it in the air and then spinning two times?
Having a middle point in sight can come in mighty handy!
Also, she might consider getting lessons from someone who is already on the majorette line at her school prior to try-outs. She likely already knows someone already on the line, and that person will be her best coach and moral support. If she doesn't, now is a good time get to know someone anyway!
I wish her the best. Good Luck!
-dbt123