Apparently, feather-sexing in mixed breed chickens does NOT work. Two out of three babies turned out to be roos. At eleven weeks old, one of the roos viciously attacked the little hen. Poor Rose lost all the feathers, and much of the flesh, from her head and neck. She is now in isolation, trying to heal. While I tried to catch her, the roo continued to attack. I had to hit him with a broom a few times to keep him away. Awful!
It's been a few days, and Rose is doing well. She is alert with no signs of infection. We continue to keep her isolated from the other hens to keep them from picking at it. The roos have been evicted, and are now living at a friend's farm.
In the meantime, Lucy has gone broody again. She is sitting on eight eggs, due to hatch around July 17. I have no intention of keeping any of the babies. At about 5 or 6 weeks, whenever she is done "mothering" them, all the babies will go to the farm.