J.S.
Are you sure it's a skin allergy? You should have her checked because it could very well be eczema. It looks like a skin rash, but it's not and can be helped with a cortisone cream. If it is eczema, be on the look out for asthma as well. They go hand in hand most times. The other thing it could be is a fungus. You should really have a doctor check her out. My son had both at different times and it looks very much like a rash, but never goes away. If it is just diaper rash, the best thing for that is Borofax. You can only get it from the pharmacist (non-prescription). Nothing I've ever used has worked better. If they don't make it any more, have your pharmacist suggest something similar. Good Luck