Sarah can I ask you what hospital your daughter is under?  Do they monitor your daughters blood pressure?  I am sure if she were getting too much salt this would give her high b/p. Have they done the b/p sitting and then standing to see if it drops?  Have they measured how much salt she passes in her urine? It seems that different consultants in the UK use different normal levels for renin. If she is not on enough fludro, it can make the 17 OHP levels harder to control.