After much debate, and the fact that temps are heading into the 20's tonight, I brought Iris and the eggs inside.
She is now in a large cat/medium dog crate with a brand new cat litter pan as a nest, and a dark towel draped over the crate.
She can stand up with room to spare in the crate, the litter pan keeps everything in place in the nest and there is space in front of it for food & water bowls and a poop area.
She has dropped some weight and by keeping her inside I can make sure she's eating enough.
The plan is to take her out to the run for 10 minutes a few times a day to let her stretch.
Yes, you are! I have a special broody pen inside the nursery coop for just this thing. I did it exactly that way for Sunny when she hatched out two little Barred Rock babies. She moved off the nest the day they hatched and rolled the eggs onto the floor for some reason, as you see in the 2nd pic.
See that small cage on the right? That's the broody pen. It's good sized and worked very well.
That's a good manageable number of chicks for her to care for, though. Sorry about the others. I sure prefer to let them hatch some than to try to break a determined broody up. Sunny almost died the first time she went broody. Never again! If she wants chicks that badly, she gets chicks.