Lethargic chicken with eye shut and feathers missing

[Kuritsa y Utochka]

I noticed some missing feathers around the head/neck area of my hen Charlotte a few weeks ago, but didn't think much of it as it happens to my flock sometimes. Yesterday, I noticed that Charlotte was acting very lethargic and spending much more time resting than normal. She also had one of her eyes shut ~90% of the time, occasionally opening it for a second or two. Today, she is even more lethargic, her eye is shut even more often, and there seem to be some more missing feathers than yesterday. My other hen Wendy has no missing feathers or shut eyes, but she was very lethargic during free-range time today (she remained in the same standing position for half an hour while the other chickens walked around).
Please help me figure out what's going on. Going to the vet is a last resort since money is tight. I've inserted some photos of Charlotte and one of Wendy. I purchased them from a farm ~2 years ago as young adults. Thanks!

 

[Eggcessive]

Can you look into her eye for any bubbles or foam, or any gunk? Look for any injury to the eye or surrounding tissue. Rinse it with saline or an eye wash. She looks like she has been picked on. Do you have a rooster? Is she walking with a wide stance or more upright? Is her tail down or up? What do her droppings look like? Has she laid eggs recently? Can you offer her some scrambled egg and some very wet chicken feed mixed with water?