The early puberty years are where the majority of growth occurs, as I understand it. Time will tell...Good Luck!
I know that for me, even if my hips didn't get better, I'd still want HRT as early as possible. Heck, I'm in my high 40's, and I have a pair of capris that wouldn't stay on my "hips" until about a week ago...now they do. Fat? or hips? Don't matter, if there's *something* there that reminds one of hips, I'm happy!