I have a group of girls - four of them - all about 5-6 months old that run around together and share a coop (3 Ameraucanas and a Buff Cochin). I have tried to integrate in a young sexlink hen that I rescued a month ago (she is probably close to their age, maybe a bit younger). They are not having it. They try to fight with her. Will this ever change? Is she just too young?