your daughter is having enlarged adenoid.
which are causing problem like pus in ears then you must consider in getting them out. Your daughter must be (what i think) mouth breather in night and snorer.
Adenoids are for protection from infections in young age ,upto 7 yrs of age. But if they are enlarged at age of 9 yrs. and causing this much blockage of nasal airways that means that they are caring infection in then and which the body is unable to fight with in this case you must get the adenoids removed by surgery- Adenoidectomy
Otherwise these adenoids having the bacterias in them which are secreating toxins also doesnt allow the child body to grow properly
secondly because of enlarged adenoid the oxygen
supply to body is decreased and so the growth is less and also there is mental slowness.
Thirdly due to enlarged adenoids there can be more snoring
that will lead to reflux of food contents in pharynx (throat) and then complications like recurrent coughing,burning sensation in throat and chest develops.
So meet an ENT surgeon and get her checked for tonsils also and if enlarged go for surgical removal.