My son has been treated since he was 10 days old, has been on the cortef and florinef (he’s salt wasting).  He’s had an elevated bone age of 12 also for some time and has finally caught up to it, he just turned 12 last August.  He too is struggling with his size 16 pants, heavy waist line and short height compared to his classmates who are shooting up in height.  He started puberty at 10 and was put on monthly shots of Lupron to stop the puberty.  This has made his "feeling short" even worse since he knows the Lupron is "keeping him from growing".   But we’ve explained that his time will come, very soon, and it’s in his best health interests.  I think keeping him in the loop of everything that his meds do has help him to understand and deal with his CAH.  I’d try the Lupron.  It’s really working for my son and I think he would have shot up then stopped growing like you are worried about with your child. 

Good Luck!  KBA