In the beginning, their health may not be so affected.  They would just show  accelerated growth, and this may start with small growth spurts, but as time progresses and androgens elevate to higher levels, they are exposed to much more and I feel their growth spurt would pick up and then their health may be compromised at that stage.  This is because the androgen to cortisol ration is much higher and things may start to be in such deficit that every time they are sick, they make higher levels of androgen.  The Pituitary would therefore in turn be stepping up the tempo more in that case and demanding huger amounts of cortisol.  So whilst your two year old seems to cope now with illness, a year or so down the track, untreated she may have complications and be simply unable to mount a sufficient stress responsed.  Infact as each illness crops up in her life, untreated she become more susceptible and that much closer to precocious puberty and so on.  

Some signs of early puberty may be changes in body hair color and density.  It is hard to tell with fair haired children though.  My son has very light colored hair and we did not see changes there when he was under treated.  Eventually there was a stench like adult body odor from arm pits and inappropriate behaviour, but this had obviously taken some time to escalate.  Blood tests are the only thing that will tell you if this is happening for sure.  It is not really much use looking to other symptoms as sometimes they may not be apparent until it is well advanced anyway.  You would be wiser to have her tested at least 6 monthly for peace of mind and knwoing that only 6 months will elapse before any problem is picked up or things are noticeable.  that’s if the sympotms do not of curse show that I have mentioned above.  

If you have kept a record book of your other daughters growth since birth, you are extremely lucky as this will be like a blue print to compare yopur other daughters milestones against in effect making it easier to pick up accelration of growth as it occurs.  It is more than likely that if she does have CAH, it will be of similar severity to your other daughters and therefore ages and stages stuff will count here.

regards,

Anne-Marie