In emergency medicine (for people), snoring respirations following trauma are a sign of a serious breathing problem. For people, we use a "jaw thrust" method to move the lower jaw forward which opens up the airway. This is the temporary fix until they get to see an ER doctor.
I'm not a chicken expert, but I do work on an ambulance, and if this were a person snoring after a trauma, we'd be hauling butt to the ER. There could be swelling or other injury to the airway, which may or may not become fatal. Main concern is that your hen is able to maintain her airway.