This is not the right thread to discuss brooding problems, but what I usually do is make some sort of separate space in the coop around the nest the stubborn lady is sitting on. I make sure no other chickens can get to her, but one. I place an older chicken that isn't interesting in sitting on...
...you name your roosters after handsome men, because you think that will give them more chance with the "ladies".
(Mine are named after a famous Dutch soccer-player, Dirk Kuyt, a famous dutch presenter, Humberto Tan, and the legendary Humphrey Bogart. Before I had roosters, who died here...