your daughter seems to be suffering from flu
...which is mostly a viral infection...in children though this infection takes a longer course due to less immunity in them...however jus give ur child plenty of fluids to drink and and anti allergic syrup...give her saline nebulisation which will help in secretions from lungs to drain out with cough
...an antibiotic is usually given to prevent any secondary condition...it will not affect the course of illness...in addition give your child some multi vitamin syrup to boost her immunity and keep her diet rich in nutrition...and the infection shall subside on its own...however if she develops a fever
,,,,then u need to get a chest Xray and CBC to find out the root cause...only then antibiotic is prescribed..
hope ur child gets well soon