Where are you from if you don’t mind me asking? If I may suggest if your endo. truly does not have any explanation at all, you should seek out a new endo. Go to CARES FOUNDATION website. In a few minutes I will post that website below and then another one for you to go to. If your endo. has no information for you, then you need to educate yourself in CAH. Your daughter’s life relies on it. 

All girls born with CAH has some genital "difference". Some have fused labias, some have extremly large clitoris’ to the point the doctors mistaken their sex as male at birth. The different levels are identified in what they call "prader numbers". The severity is rated from 1 to 5.  5 being most affected. Some that have the severe end of this spectrum can seek surgery to correct the genitals by their choice especially when it brings on urinary tract infections, some do not. It sounds to me like your daughter is mildly affected. At birth most genitals (girls and boys) are naturally swelled and large. Then the swelling goes down a bit. The medication will not allow the clitoris to grow anymore as long as her medications are giving properly. Also I believe she will slowly grow into her clitoris if it is MILDLY affected. Congratulations on that baby girl of yours. Love her to pieces. They grow up way too fast.