M.P.
She does not have a brain tumor. What did the doctor say?
some kids are just more sensitive and throw up more easily when mucous and something touches their uvula at the back of their throat. Coughing will cause those sensitive to throw up. I would try to relax and not worry.
It is extremely rare for a child to have a brain tumor. Dismiss that thought from your mind so that you can have peace of mind.