Here are my girls. It's the cuckoo
maran that thinks she is the boss of the world. They are all around 14-16 weeks. View attachment 1439211
Cute Pullets. Just in case you don't know, female chickens under the age of 1yr old is a pullet.
I pulled a photo from one of your other posts - this is your coop and run correct?
How much space is the coop portion (sq. ft.)? What is your weather like - a general location is helpful (state/country).
Chickens are creatures of habit, you will have to be patient and round them up at night, they will eventually learn where the need to be. Mine go in when it's quite dark, but with youngsters they can get a bit of a stubborn streak and decide they want to roost outside of the safety of their coop. Yes, the others will follow the leader, so you will need to work with her. Put her in the coop first, the others will go. You mentioned they used to go in by themselves, but have stopped. If the coop is hot and ventilation is poor, then birds are less likely to go in too - those are things to consider.
I have never had a hen, much less a pullet be aggressive toward a human, so that's a new one to me. If she is aggressive, a time out is not going to work- you are only separating her from her flock-she's not aggressive to them correct? Give her a swift peck to the head with your finger to correct unwanted behavior.
