i think you did a great thing taking her to get it waxed. she wouldve felt pretty special! she is obviously self conscious of the hair, and being teased can do a lot of damage, i dont think there is any harm in it whatsoever, is teaching her to talke pride in her appearance in a sensible way which is a good thing, and great that she asked you before she did it.

I dont think hair removal will make her grow up any faster than having her period and large breasts at her age would if that is what you DP is worried about.