C.M.
It might be a yeast infection but you need to go to your ped to get that diagnosed. If it is yeast, then the ped will give you a script for anti-fungal cream.
You could also try baking soda baths (a small palmful mixed in with the bath tub water) and then let her airdry.
C. M., CBE, CLD
www.westsidebirthconnection.com