I would definatly keep her separated, as she has nowhere to go to escape these attacks with that many birds in that closed space.
She may be just unlucky and at the lower end of the pecking order. Flocks sometime single out someone and can get brutal, even resulting in death for the victim.
she needs to be compleetly healed before you attemp to re-ontroduce her.
do you have a pen or other enclosure for her? If so it would be best to separate her along with a non aggresive hen friend for a while.
You may have to eventually rehome her as sometimes these personalities are just never accepted back.
I would catch her, clean her wounds, put healing ointment in her. (This needs to be done to keep flys off) fly strike will kill her.