If it only lasted for a few minutes it possible she inhaled feed dust or got something in nares/trachea. If you're feeding a crumble feed that contains a good amount of dust, you may switch that out for a pellet-feed.
Have a video of the hen? Have you tried checking inside her mouth with a helper, and a strong flashlight for anything abnormal?
Out of all problems that can cause respiratory distress, Gapeworm is one that is not seen very seen often, but if you would like to treat for it, you could use...