Fever since 6 days. Fine pls advise.

Hello, My son got fever and cough and we gave him antibiotics and he got well in 5-6 days , after that my daughter is 6 years of age, she got fever on Friday after coming from school, we anticipate is flu from my son, so consulted the doctor and started antibiotics next day since fever was repeated and was 102 til 104. After taking two days of antibiotics from Monday she was feeling much better and fever was almost gone ,doctor told to take antibiotics for 5 days aupen Ds syrup two times a day . We sent our daughter to school on Tuesday and after coming from school she started sneezing and coughing badly in the evening I checked her fever was 100 again , we started giving fever medicine and antibiotics course , today is Wednesday 5 days of antibiotics course is over ,but still fever coming up after 6 hours . We checked doctor again he said she has alot of chest congestion and now doctor changed another antibiotic Azithromycin from tomorrow. Hope treatment is going fine pls advise.