Hello, I just read your query. The symptoms you have mentioned here persistent fever, vomiting and frequent urination are suggestive of urinary tract infection which is very common in children. * So perform urine routine examination first and do visit a nearby pediatrician. Because according to urine report he will prescribe you appropriate treatment and if she further requires any investigation your doctor will let you know. * Till then for high grade fever you can give her syp. paracetamol and can do sponging and give her only liquid and semi solid diet. * I hope you find my answer helpful. Thank you.