Here is a page that talks about Cat starting pitching at age 11 and getting cut from an All Star team. I think she was probably a little bit of a late bloomer, but in general they started later than kids now days.
Cat Osterman - Fastpitch Softball TV
The top how-to source for Cat Osterman , free fastpitch softball videos. How-to videos about softball training, softball pitching, softball hitting, and more
fastpitch.tv