You have not mentioned age of child. However see that dehydration doesn't take place. Give max coconut water in piece meals, give boiled, cooled water, add sugar, lemon, tulsi extract (optional), salt in small qty in a glass of boiled cooled water and give her to sip every minute or two. Give vomiteb sy of ayurved charak co three to four times a day as per age. Give semi liquid khichri, daal water or whey water, meera water etc. In case of need pl call or chat at Lybrate chat.