I didn't realize my Broody Girl was full-fledged Broody until she didn't come out from under the house one morning. She'd go there in the evening and come out during the days, but then she just stayed there for 5 days before coming out!
She's never been the overly aggressive type of Broody, maybe because she's a pet. She did try to escape the coop today, hoping she could scare me away from the door by charging, but it didn't work. She is eating spinach and arugula well, and I gave her some plain yogurt to help with her intestinal health.
I have read that roost mites kill more chickens than anything else.