It is obvious she has some sort of respiratory disease. There are a few of them, each with some different symptoms. Silent gasping could be sign of aspergillosis, a fungal disease from mold. Others are infectious bronchitis virus, mycoplasma gallisepticum (MG,) coryza, and ILT. Do you see any bubbles or foam in her eyes? Is she sneezing, or having rattles with breathing?
Do you smell any mold in the hay that was added to the coop? How is the ventilation in there?
Do you smell any mold in the hay that was added to the coop? How is the ventilation in there?