11 year old girl with Chronic (wet) cough for 3 years

My granddaughter has mucus in her lungs and a constant cough trying to get rid of it. It started as a cold about 3 years ago. After several courses of antibiotics it went away. Reoccurred and treated with antibiotics several more times and usually worked for weeks to several months at a time.
At some point it became constant congestion with her having to go to the bathroom or outside to spit out the mucus. The mucus is clear or yellow; and at times, foamy. Antibiotics always seemed to work short term, but eventually she was tested for CF with a borderline sweat test result, and then underwent genetic testing for known CF variants. This showed that she did not have any "known" variants. She has been through allergy tests with nothing found and been on meds for allergies that did not seem to improve her condition. Her bronchioscopy showed that one airway is smaller than the other and this was given as a diagnosis. The hope was, that it could be outgrown.
Since the symptoms did not start until she was around 8 years old and began with an illness we sought a second and third opinion. This led to her being put on inhaled steroids for asthma. Her response to this was that she began having asthma attacks which she had not ever had before.
She was a born prematurely, had low birth weight, and spent a couple weeks in the hospital before coming home. But she was completely healthy until the original illness that started all this.
Were antibiotics not administered for long enough or not the right ones?
Every few weeks she gets a low grade fever and feels too sick to participate in normal activities, but otherwise, her only complaint is congestion and cough. It has kept her from many important events and caused her much embarrassment. We fear irreparable damage has already been done to her lungs. Can someone please help!

[margypops]

I think you would get more input about your concerns if you seek help on the expert/doctor forums ,I have asked them to put your thread on the correct one .Good luck I hope you find information how to help your daughter ...