I'm 5'6 and at 15, and my 12 year old brother is 5 foot. I don't think cf stunted my height because I'm just average if not a little taller than most girls in my grade. Before I knew i had cf and i had malabsorption, my weight went down but my height never seemed to. In fact, now that I am taking enzymes, I've grown another half an inch in about 3 months! My dad is kinda tall, so it might just be in the genes too.