One thing I noticed is that in some species of animals, the lowest animals in the pecking order tend to be the hardest on a newcomer. I have three horses. We added a fourth, and the omega in the herd chased him mercilessly for at least an hour. The finally both got so tired that they stopped, sniffed each other all over and were fine after that. I think your hen is irritable because of being broody. But, as Ridgerunner said, your cockerel is a little boy in with women. They teach him some manners before they accept him.