Is vet care an option for you? They could test to see if it's viral or bacterial and try to ID what it is.
I would crate her now while you try to figure it out. Did all your birds come from the same place, at the same time? What other symptoms are you seeing? If you can contact the person you got them from, I would ask if they have respiratory illness in their flock.
If there are/were no other symptoms then it could just be an eye injury, but since you say there are other symptoms, then likely respiratory. She does not look like she feels well.
Use sterile saline to rinse the eye, apply warm, wet compresses to loosen the gunk and clean her up. See how the eye itself looks.
If you suspect a respiratory virus then you can try treating with a tetracycline medication (Doxycycline and Tylosin are common ones used depending on illness), and I would use some terramycin eye ointment in the eye a couple of times a day, most tractor supplies carry it. If you can't find that you can use plain neosporin in the eye same way.
Some respiratory illness's are chronic and treatment only treats the symptoms, the birds remain carriers, so they will become symptomatic again during times of stress. If it's one of those they remain contagious and will expose any other birds you bring into your flock.
You can get some medications for respiratory treatment here:
https://www.jedds.com/product-category/poultry/healthcare-poultry/medicine-poultry/