I've spoken to the hubs at work about dividing the coop and it isn't an easy endeavor...
I've also spent the whole day in the coop with the girls. The lowest girl on the pecking order is the nastiest to them.She will be placidly doing her thing and just run over and peck one, then go back to her thing. My middle hen is the friendliest. Just goes over, hovers, and leaves. I've put the big girls out for their daily play time for a few hours in the yard and the pullets are free to roam the coop and run.
Since dividing the coop isn't possible, I'm thinking of putting the big hens into the goat pen for a couple of days. They love it in there. It's big, has ground they love to dig and dust bathe in and it will give the pullets time to establish the coop as home. It's easy to put in temporary nest boxes for them in the goat pen and the "run" is larger than the current run for the coop. Thoughts?