We have a normally very happy chicken coop. We bought chicks this past April and raised them together. We have six hens: 2 Rhode Island Reds, 1 Dominiquer (?), 2 Golden Buffs, and 1 Cochin Bantam. We also have a Cochin Bantam rooster. At first, the Cochin Bantam hen was the dominant hen. Now the other girls have started to fight with her. They are very aggressive and peck her feathers out. She's absolutely terrified and won't come down out of the coop. She is very small, she only weighs about a pound. The other hens are full-sized ranging between 3-5 lbs. I am worried about her because she is so small. Will this stop or is it some phase they are going through? I don't want the other hens to hurt her badly. I need some advice as I don't know much about chicken behavior. Thank you!