Fever is generally divided into 2 groups, in a 7 year old child. I assume the child has been going to school. Our first task is to decide whether it is a ordinary fever or a serious fever. There are 3 simple steps. Any fever more than 104 degrees F is high and below 102 is low. In between it is moderate. You can decide on this. That degree is not important. When giving paracetamol the childs fever should come down and the childs activity should go up. If this happens, it is most probably ordinary fever. Then what are the extra symptoms she has got, apart from Rib pain? Rib pain could be a part of viral fever. If the lungs have been affected she should have cough, breathlessness or a wheeze. Watch for any vomiting or urine or motion problem. Carefully scan her skin for any red rash. Look at her limbs and see any swelling is there. You can ask her to open her mouth and see whether there is anything abnromal in the throat. you can feel her neck for any swelling. If all these are negative, then it is most proably viral fever. As regards to the pain, not only the rib, anypart you can follow this rule of thumb 1.At the place where there is pain is there a swelling? 2. Is the skin red? 3. On touch, does the child wince with pain or with deep pressure with your fingers is there any pain 4. Watch carefully how the child uses that part. If it is free, painless and the movements are full, the chances of illnesses is less.