Fortunately, it all looked a lot worse than it actually is. I cleaned the eye with cotton wool soaked in Colloidal silver and found that the injury is a very small nick in the upper eyelid and her main problem was that the blood pooled in the corner of her eye was affecting her vision, hence the constant rubbing/scratching with her claws.
Once the eye was cleaned up, she stopped rubbing at it.
I kept her isolated in a small cage for an hour or two, just to make sure the wound had scabbed over, and then put her back with her mates where she immediately stuck her head in the feed hopper, none the worse for wear. I think this will heal without spoiling her looks. I hope so, anyway.
It was interesting to note that just before I went up to check them, one of the cockerels was crowing incessantly and then I arrived to discover this injury. I wonder if he was trying to get my attention because something was wrong?
He has been known to crow nonstop when the feed or water dispensers are empty, too. The lack of feed and water was not the issue this time though. Makes me wonder...