The pecking order

I am trying to introduce a new hen, but the pecking order is very real and rather nasty. Tends to be three hens attacking with at least one on her back. These marks are the battle scares. There was blood over the top of her head the first day.
They are ok with garden space, or roosting at night. I will gradually acclimatise them I hope, but mostly keeping her separate. She thinks inside our house is a good place!!!

Shame as she has a lovely friendly personality. She has laid two yolk less eggs and one standard one. Did not know they did this.