Racermom, How did the race go? What did you end up doing? Were you and your daughter satisfied with the result?
I agree with much of what has been said:
The chamois absorbs alot. A first period is likely to be quite light making the chamois enough. Tampons are a perfectly acceptable hygeine product for a girl of 11. I never wore a pad in my life. Started right off with tampons. Then when the knowledgable women of TE introduced the diva to me I switched. Diva would not be a sensible choice for an 11 year old. (at least not for the usual 11 year old.)
Hope it all worked out.