It's probably wise to see your vet as she might have an allergy to here normal diet, or could even be something from the garden. Flute had a slight problem of this nature, and the vet recommended a change of diet and also to wash her with this shampoo called "PYOHEX" it's a medicated foam for dogs. You would have to get a similar type available in the States though as this stuff is made in Queensland. Again your vet would advise you on which brand.
Hope she feels better real soon.