Pecking hard. Need help

[Salman93]

Her head was covered by blood.

 

[Latestarter]

She needs to be removed from the rest and kept in a safe place to have time to heal. You need to clean her up and apply something like Blukote spray (Not sure you even have that there) or something that can change the color of the area away from bright red. The other chickens see blood and they will attack it. Chickens can be quite mean and are ruthless, like the dinosaurs they descended from. They will attack weakness.

Sorry your hen got bloodied like that. I hope she can recover and be re-integrated back to the flock. I would also try to determine the main attacker and send that bird to freezer camp. Just me.