Help - my Orp is in distress - need answers

[The Vargas Chics]

Thank you for all the input. What do the lice or mites look like? Is there a photo to look at? I will google and see what I find. How do they get the mites? When I put her in the pen with the others they all start pecking at her ripping feathers out at times and going at her with their feet. She runs for the coop to hide. I'm keeping her out until I can get her vent area healed up, so they don't peck at her. Friends & family that have chickens told me they will attack the weak and sick chickens. They had that happen to one of theirs. She hasn't laid any eggs since this all began, I've cut back on her daylight hours so she doesn't lay that often until all cleared up. Thanks for all the help. Monika