Emily's drs do believe in the possibility of some carriers being symptomatic. This is in debate for Shawn, actually, with his dx being up in the air as it is (sweat test results of 48 and 54, chronic sinus issues, one known mutation. We only know one of Emily's mutations but her symptoms are so much more pronounced, and she had a much higher sweat test result.) We don't know if he has Emily's mystery, 2nd, mutation or if he's just a carrier.
I agree with the others though, in that it seems that this is much less likely for your daughter. I agree with getting a copy of the xray report (and any other testing she's gotten, actually) and getting a 2nd opinion for your daughter with a pulmonary dr. that is well-versed in CF. Even if this one works all day with CF patients, for whatever reason she doesn't appear to be very open-minded- or at the least, she is not communicating very well with you. She won't even tell you what she DOES think is wrong if it's not CF, and that is a red flag to me.
It's SO frustrating having to go through so much in getting appropriate care and treatment for your child...