Thank you for your query on Healthcare Magic.
Loosing weight and with prominent belly of your child needs pediatrician
Vomitings are also there so needs a compete review of her diet, history, physical examination and a detailed investigation work up to look for the causes of her weight loss
What is her present and recent previous weight?
Is she suffering from any underlying heart, respiratory, or chronic infections?
I advise you to consult your Pediatrician for complete examination and evaluation for the weight loss.
Hope I have answered your query.