I only have Japanese Bantams and the broody hen poop is like a really smelly huge poop.She has a branch in there to sit on, she's got on it a few times but got back off again. She's been sat in their own coop and left alone for a month, I only brought her in yesterday. She's not bothered about me being here, its just me and I'm not walking around a lot. If I drop bits of roll in in front of her she will eat some, she is broody because she's been resolutely sitting on the eggs of the other chickens, pecking and growling at me when I go to collect them, plucked out her belly feathers. Even with no eggs in there now she's still sitting like there's eggs under her. It was really hot out in the coop, but much cooler here in the house. She's happy otherwise, preening, making mummy calls, he comb is still red. There was one bigger poo in there this morning, but not huge and not stinky, but then she's only a little banti so there no it going to be huge.
Can you put in a wire floor for air circulation under her?
The problem is if they can get comfy and get some warmth under them they will like to stay broody.
Maybe keep taking her out in the kitchen as a change of scenery for a few hours at a time (with food and water). That should make her forget her nest.
Mine always break after less than 4 days in an all wire dog crate, with wire mesh floor - out of sight of the nest.
Maybe if you block off her nest box in the main coop, then put her back in she will go back to normal soon (because she can not get into the nest).