Can we see a video? (upload to youtube or vimeo, and post the link, BYC upload will not work for videos) or a picture of her face?
are her sinuses swollen?
labored breathing or a gargling sound in her breath?
is she eating or drinking?
is she laying down more than usual?
any nasal or eye discharge?
any bubbles in the corner of her eyes?
is her comb red (not pale or white toned)
you may want to gently open up her beak (from the bottom beak) and with a flashlight look down her throat (it may take a long time for her to sit still and let you open up her beak without snapping her head way from you, don't get frustrated, just keep trying, she'll eventually let you.)
Is there anything you can see blocking her throat?
you may also want to look for gapeworm in her throat.
I just recently had a girl start sneezing and sitting down more often, no other symptoms.
Took her to the vet after finding her nearly unresponsive one afternoon, turns out she had an awful respiratory infection. vet gave us antibiotics, and she lived through it.
vet said if she were any worse she would've put her down, since she is already hitting 10 years old.