If she seems normal in the morning I would let her back with the others. I would not do antibiotics unless you see signs of illness. If she's getting kept from food or water by the rooster, or other birds, then add some feeders and waterers so they can't all be guarded and she has more chances. Monitor her weight to make sure she's gaining over time and not losing more. Weight loss could be from that or possibly from internal parasites. If the roo is a problem I would separate him. How many hens do you have for him? How big is your coop and run?