Hi there..I can understand your concern. Looks like she is suffering from acute gastroenteritis. In this condition it is important to keep him well hydrated(ask her to take plenty of fluids like water, coconut water, ORS solution) and provide only home food(more of curd rice). Start her on probiotics like capsule vibact, twice daily after food, for 5 days. If the condition doesn't improve in two days or it gets worse, kindly consult a general physician for further evaluation. She might need oral antibiotics.