If it doesn't clear up maybe take her to the Dr as girls can get a dermatitis from moisture/urine which can cause irritation. Otherwise as much as its a PIA I'd say lots and lots of nappy free time, maybe if you've got a hard floored area just sit with her for a while and let her play with toys in the nuddy on the hard floor so if there's an accident its cleanable

Goodluck!

*hugs*
Cailin