Some Intestinal infection seems to cause it. Pl give her light food, warm water drinks. Prefer to boil some carom/ Bishop s weed seeds (Ajwain) and allow this water to drink. If not palatable, may add honey. If I were your family doctor, I had insisted to give her child friendly Balchaturbhadra chooran which is a classic four herb combo for children. It s given in small doses twice to thrice a day with honey or water. It cures vomiting, fever, stamachache, lose motions, cough of seasonal or infectious nature. Creates immunity. Safe n harmless. It detoxifies the digestive system and enhances metabolic activities. It s commonly available in India or can be ordered on net. Hope its helpful.