Sorry to hear aobut your troubles. Try scrambling an egg for your hen, tempting and good for her. Hopefully she drank the water if her cage is not wet. All you can do is try, some birds have more fight than others, and shock alone can do a bird in. It really isn't that your birds are mean, it's their nature. Once a bird is pecked enough (or injured) that it becomes red they will continue to peck it, even to death. Hopefully she perks up in a day or two.