By day 3 I was already chasing them back inside the fence. This was day 4 four after about my third chase. I scolded Mom & Dad... but all they did was hiss at me! LOL
Merlot, it's really best to separate a sitting hen from the others. Were they after hatchlings? or eggs?
I've been able to "break" the broodiness by either just tossing her off the nest every time you catch her there or put her in quarantine, a wire cage with food and water but
no nesting material, just bare wire and a roost for her to perch if you can. Three days should do it. If you see her on the roost sooner, you know the broodiness is over.
I had a cage I hooked up on the wall of the coop. This way she was still 'in contact' with the group (sorta!) and you didn't have to worry about re-integrating with the flock so much.