coughing causing vomitting

my daughter has had a cough for about 2 weeks now i took her doctors who  gave her amoxicillin it didn't do anything so the following week i took her back but by then every time she coughed she was sick, it was only water at first now sometimes it is what she has eaten too, the doctor gave her cefalexin which has helped more than the other medicene but she is still vomitting while coughing specially in the morning, dueing the night and if she runs. This is getting to us both and i'm now getting worried her tonsills were quite swollen too but they are getting back to nornal please help.

[National Jewish Health]

The cough could, as you suggest, be the cause of your daughter's vomiting, either by size and pressure on adjacent throat structures or because of excessive mucous production.  A throat culture might be useful.  On the other hand, she could have infectious bronchitis or pneumonia, as a cause of cough or she could even, despite prior vaccination, have pertussis, commonly called whooping cough, for which amoxicillin and cephalexin are not the most effective antibiotics.

That her tonsils are "getting back to normal" is a good sign that she is on the way to recovery.  Nevertheless, the use of an antitussive, commonly called a cough suppressant, could reduce the frequency and intensity of her cough and with that reduce her vomiting.  In the meantime, dehydration probably poses the greatest risk.  You should watch for this, such as skin turgor, dry mouth and tongue and reduced urine output.  Contact your daughter’s doctor if you are at all concerned that she is becoming dehydrated.