I wouldn't unless you're in dire shape and going for a 'Hail Mary' move, but then... I don't really know the answer to that question. Hoping that someone who does will chime in on the subject. Be advised that Corid treats coccidiosis ONLY, it doesn't treat other types of worms like ring worm, tape worm, gape worm, etc., but it IS the most common ailment among chickens and rears its ugly head with young birds and birds that are immuno-compromised from another, unrelated illness. So there's a third medicine in the mix if you're going to treat for 'everything'.
How's she been laying? I know that sounds unrelated, but if she's dealing with infection internally, that infection can squeeze any number of her nine air sacs and/or one or both lungs and cause difficulty breathing too. (Another vote for antibiotics) Problem with chickens is that so many of their symptoms overlap!
