Diarrhoea in infant

If she is otherwise feeding well and having plenty of wet diapers, it may just be a viral infection, which can cause diarrhea along with a runny nose and cough. Keep her hydrated with frequent breastfeeds or formula, and keep an eye on her wet diapers. Since it’s already been 3 days, I’d check in with her pediatrician, especially if the stools are very watery or she seems less active.