My 3year old daughter has fever and a wet cough. last temperature was 38.4c she vomited twise within the last 12 hours. any suggestions on medication?

Not particularly: The data shows most if not all cough meds promoted for kids do little or nothing. They can give you something to do but little more. The most important issue with a sick kid is making sure they take enough fluids to stay hydrated. This sounds viral & should pass. Ice chips, a little honey with lemon or chocolate helps a cough.