Polka slept out with her brood of 5 last night, and they all lived to tell the tale. She was the one who incubated and raised Fez outdoors 24/7 for her first 6 weeks, till I persuaded them to use a coop. She has been laying in a coop since, and I thought we had cracked this problem when she chose to go broody in a coop (and I wanted to reward her for her choice and not inadvertently drive her back to secret nesting, hence that brood's existence).
The night before, she and Oxwich were in neighbouring nest boxes in the same coop, and I thought that was nice if unusual (most nights each broody has selected a different coop) and wondered if they might even engage in some communal brooding, but evidently it was not an experience Polka wanted to repeat, and she preferred to go it alone in every sense last night. I wonder how it will go from here
(Fez, Polka's wild child and only previous brood/solo, has laid in a coop, is brooding in a coop, and shows no signs of following her mother's inclination incidentally. She is at 5 weeks now, and left her kids last year at 8 wks, which is very short for here. I'm curious to see if she hangs in there longer this time.)