My hen has gone broody....but something seems fishy!

[BreezeDancer]

Hey guyz! My Aseel hen just started sitting on eggs today. But she is sneezing....is she sick???

 

[Ol Grey Mare]

Welcome to BYC....so gad you've joined us.
There are a few possible things going on here with your bird. The first may be that rather than broody she is feeling ill and has retreated to the privacy/protection of the nest due to the illness. Are you seeing behaviors other than simply the fact that she is on the nest that indicate broodiness -- if you approach the nest, what does she do; if you remove her from the nest, what does she do?
Assuming she is, in fact, going broody it is possible she is developing a respiratory issue at an inopportune time -- are you seeing any other sypmtoms? How do her eyes look - any discharge, swelling, etc? Is her breathing sounding normal? Are the sneezes few and far between and dry sounding or are they frequent and wet sounding? Is there anything that is potentially irritating to her nares in the area she is nested or an unusually high dust level in the general area?