Thanks for your responses!
I have thought she was broody as she's been this way for weeks and weeks. But after that other one died I wondered. I have been letting them free range in the mornings and making her go out. I felt for an egg and I don't think that's it, but I'm not exactly a pro at this.
The coop area is approximately 6x8 and the run is 24x10. It's all brand new this spring. I am confident someone is picking feathers. I personally think it's the original 5 hens that are definitely the queen bees. I use a 16% non gmo layer mash. They also get scraps almost daily. Should I give them canned tuna or something daily? They didn't like the cat food I tried at one time.
I dusted the ones that I could catch, which was about 10 of them and I put dust where they like to dust themselves. I've looked for lice and mites and don't see anything that looks suspicious, but again, I could be wrong!
Also, I have 15 hens.
The co-op that I purchase the feed from have taken great lengths to test the feed and say it's a great product, but I don't know?? I would love to have those nice fat hens I see pics of. I have a few that look good, but many of them have something that's weird.