Is it maybe a yest infection. Try some lotrimne sp? that worked great for my daughter. I was told to do hydrocortisone oitment and lotrimne do one every other diaper change. also try making her wipes sometimes the stuff in wipes can make them not go away. I dont buy wipes I just make them. Its cheaper
Here is how to make them
http://www.mainstreetmom.com/budg/wipes.htm