Thanks for the query
The description you have provided is suggestive of supporative otitis media
which means that she is having middle ear infection
which have caused pus and discharge that has accumulated in the middle ear cavity. The fluid will drain itself after the elimination of the infection but presence of fluid delays the healing process and the infection may spread through it to sinuses
or external ear and may form abscess
therefore if the infection do not subsides with 2-3 days then it is important to have surgery which is a minor procedure simply make a hole in the ear membrane or insert a small gromet in case of repeated infections.
It is recommended to go with you ENT doctor advice