Did your hen have any symptoms, such as bubbles or foam in either eye, swelling of the eyelid or face, nasal drainage, or gasping? Can you get a short video of her breathing and upload it to YouTube or a similar site with a link posted here? How does her crop feel first thing in the morning before she eats or drinks (when it should feel empty and flat?) With most respiratory diseases, penicillin usually won’t help. With mycoplasma (MG) Tylosin or Denagard are helpful. With infectious coryza, sulfadimethoxine (Medicox) can help. Those are available at jedds.com online. If it is a virus, such as infectious bronchitis, antibiotics do not help, but they may improve in a month or so.