my 4 year old is vomiting phlegm. She stayed with my mother over the weekend and seemed fine until sunday, where she had a cough which sounded quite phlegmy. I know she has an allergy to milk, and have told my mother not to go mad on dairy, but i have a feeling she may have overdone it on the sweets, and now she has excess mucus and keeps throwing it up. What is the best cause of action to take? I am giving her fluids and trying to get her to eat dry food, but she is very fussy with food, so all i can really give her is dry biscuits. She is just over 3ft, and weighs 2 and half stone. She has hypermobility, and learning difficulties. And a lactose intolerance.