You've got some great advice from everyone here so far. I'd like to add that not only will those pesky boys pluck them bald and possibly even make their skin raw, but if they start grabbing to the side of her head, they can injure the female's eyes.
Not sure how big your coop is, but you might consider putting up a removable fence. I use some of the leftover hardware cloth from building the pen, but I'm sure even a small roll of poultry wire would suffice for this purpose. I've done this many times in my pen to give my Ruby a break (she's everyone's favorite for some reason). She hates being brought in the house away from them, but she's perfectly happy if she can still see them and they can't get to her.
