It looks like a bad case of conjunctivitis, which may be from an eye infection or foreign body, but also could be respiratory diseases such as mycoplasma (MG) or coryza. I would look into the eye for a seed pod, or a piece of dirt or grass. A tumor might also be a problem. Clean out any pus or drainage as best as you can. Does she have any respiratory signs, such as sneezing, coughing, nasal drainage, a bad odor, wheezing or rattles? Her eye may not improve until the glob of pus is removed. She also may need a stronger antibiotic, which a regular vet might prescribe over the phone. Here are a couple of threads to read about removing these pus plugs:
https://www.backyardchickens.com/t/927650/help-extreme-eye-infection-chorzya-cholera-injury
https://www.backyardchickens.com/t/1071718/nasty-eye-infection-pics