J.W.
Try buttering her up really well . This happens with my son when we introduce new foods. It usually goes away within 2 weeks or so. The stomach overproduces acid with new foods which comes out in the poo and irritates their skin. Hives , swelling,itching ,vomiting, diarrhea are a sign of a food allergy though and you should remove those foods from her diet .
Good Luck,
J.