I also have a ten year old NSW.  She is on florinef. We tried just cortef, but she was never in control till adding the florinef. There have been some studies on this. We were told although she is NSW, that there will always be some salt wasting even if minor. We also do not regulate her salt. She craves it. You must monitor their blood pressure to ensure you are not giving too much florinef.  We only give .1mg a day along with 20 mg cortef a day.