Maybe before signing her up for a certain age group club, you can see if she becomes friendly with any kids while at the terminal or before the Sail Away party. Have her check out the kids' club enrollees to see if there are quite a few 12-13 year olds in the 10-12 club or if there are kids more her age in the teen club.
If there are a lot of 15,16,17 year olds in the teen club, maybe she'll want to hang out with the younger kids more her age and "speed" if you get my drift.
Also, did you check out your cruise meet and ask your fellow cruisers?
Good Luck!