My pullet is in there all day for now. I put a small branch in there for sitting on - it's just on the bottom not attached to anything. I also have shavings in there.
I bought these coop cups from tsc last spring I believe. They come in real handy.
https://happyhentreats.com/products/coop-cups...
What about a dog crate with the plastic sides? I currently have one in my run and have an injured pullet in it. I put her on the roost in the evening after the roost rumbles are done.
I took a plastic bag and covered the holes on the side to keep rain and snow out. I attached it with zip ties.