My daughter (non-CAH) started puberty when she was just 8.  Or that’s when we noticed breast buds.  It could have started earlier.  She started growing very fast before that.  She went from being the shortest kid in the class in 2nd grade to the tallest in 3rd grade.  Well this was before the internet was what it is today and I took her to an endocrinologist who said she was going to be about 5’5", 5’6" and not to worry, 8 was "normal".  I didn’t even know early puberty could affect height.  So we didn’t do anything.  She looked like some of her friends in school’s mother but psychologically she handled everything well.  But now, I’ve spoken to other doctors and they said they would have stopped her puberty.  It’s a monthly shot which could either seem terrible or not so bad depending on your attitude.  She ended up at 5’2", but she’s lucky because we’re both tall - 6’2" and 5’6".  She also has something called PCO which has been linked to early puberty.  In retrospect, I should have found another doctor who would have given US the choice and I would have probably stopped the puberty.