When I got nasal polyps (age 13), I vaguely remember having a stuffy nose that didn't really go away. I always had really bad sinuses growing up and attributed my nasal congestion to crappy sinuses until I noticed one day that there was an obstruction when I looked up my nose. My polyps got so bad that you could see them just when I tilted my head back. Before they got bad, they would move around in that, when I woke up in the morning I could sometimes breathe really clearly because I think they ended up shifting way back into my sinuses when I had my head down while sleeping. By the end of the day though, I couldn't breathe through my nose and they were visible again. I don't think I ever really snored - polyps or not.
I don't know about the symptoms your little one is having, but I was under the impression that polyps develop after years of sinus infections. Constant sinus infections cause inflammation and the inflammation causes scar tissue and polyp formation. With your little one only being 2.5 years, my first thought is that it's just the beginning of a sinus infection or head cold. Don't quote me on this though. I would maybe have the CF doc or even just the general pediatirician do a quick assessment by looking up the nose and if they notice anything out of the ordinary, they can then recommend an ENT who will have more instruments and resources to REALLY get a good look at things up there.
Best of luck to you both!
