Fever for past 8 days. Loss if appetite.

Hi my sister is having fever for past 8 days. 1st doctor on 19th Oct- got tested for dengue and typhoid. Both negative. Started medicine for fever along with antibiotic. Fever didnt recede in 2 days. It went up to 104 Saw another doctor on 21st. Blood test and urine culture done. Started medication for infection. No progress in 3 days. All blood tests normal, Urine infection negative. Saw the second doctor again on 24th Oct. Asked for chest xray and finally concluded mild chest infection. Started Cefton 500 for 5 days. Now, on 27th oct at 1 am, fever is again 103. Gave dolo and fever is coming down. Please suggest next course of action. She is having fever, feels cold, body pain, feels like vomiting always and loss if appetite. Thanks in advance.