She doesn’t need a nest box to be broken from bloodiness. My broody breaking pen is on the ground in a 6x7 cage about 5 feet tall. It has a dirt floor and is outside and covered. I put a 2x3 inch roost in it. They spend a lot of time on the roost bar the first day or two, and then about 3 more days scratching around. They usually break in 5 days, but if they go back to a nest box afterward, they spend another 3 days. Many use dog crates with no bedding, suspended on blocks to allow air circulation underneath. Everyone finds what works for their flocks.