Hii , Welcome To HCM & Thanks For Asking Your Query Here I have gone through Your query and will try to provide information you need on it Fever is not a disease but a symptom of a underlying disease , , if she is having abdominal pain , difficulty in passing urine (burning or pain while urinating ) , Fatigue and high grade fever , most probably she has caught with an infection A fever may be of various origin including viral , bacterial , Malarial or it may relate to other less common medical conditions giving Tylenol will only give symptomatic relief I would strongly Recommend you to see Your GP , He will examine her properly and will probably carry out few blood test to rule out typhoid , malaria etc along with necessary medical investigations to rule out the underlying medical condition I hope it help Thanks & Get well Soon