I would clean the eyes as you have done (use saline if you can,) and apply plain Neosporin or Triple Antibiotic Ointment twice a day inside the eye. Look inside the eye for pus or anyworms, debris and remove it. I would go ahead and worm her with fenbendazole (SafeGard liquid goat wormer, horse wormer, or Panacur paste) 0.25 ml (1/4 ml) per pound for 5 consecutive days. That would treat most worms that chickens get. On the first day, mix some wormer with water 50:50 and apply it to her eyes. Then wait 14 days, and repeat the wormer to the eyes and give one more dose orally. That and the oral wormer will help to treat eyeworms if that is her problem.
She also could have a respiratory disease, such as MG or one of the others that may cause the eye issue. Look for nasal drainage, gasping, crackles or wheezing while breathing. Antibiotics such as Tylan 50, 200, or the oral powder can be used to treat it. Oxytetracycline and Baytril could also treat MG. Some diseases are caused by viruses, and those would not respond to antibiotics, but would have to to run their course over several weeks. Hopefully, you can save her. Keep her separated from any other chickens for a month to quarantine her. Good luck.
Edited to say that Valbazen is what to use in the eyes, diluted 50:50 with water, not fenbendazole (SafeGard.)