I can't really answer your question because I don't really remember feeling like I couldn't breath...
13 was when I started with a productive cough also around when I started to bleed. In retrospect I wish they had been a bit more agressive. Try not to feel doom and gloom about this. I wasn't hosp'ed until I was 19. I was always able to "kick it up a notch" at home with good eating, exercise and increased nebs and clearance.
How well does she eat? I suggest getting most processed foods out of her diet.
How active is she? She should be working out at least at an aerobic level for 30 mins 3-4 times a week.
Does she participate with the Vest ... meaning huff breath after cycles and get out goodies? Does she do something for clearance since technically Vest just shakes it up? FOr ex, flutter, acapella, autogenic drainage?
Now's a good a time as ever to start researching alternative therapies. It's going to be a long while until the medical community embraces it so we better just step up to the plate ourselves.