PS - of the other three, two co-parented four chicks together. The third just raised her own, but they were all good neighbors. All the broodies were Buff Orps. Go figure!
Yikes, sorry this happened. We had 4 broodies at once, one year. One of the broodies was horrible and not to be trusted around any of the other hens' babies, at all! We had some tall, strong sheets of cardboard. We put a wall around that one, pronto! She could hear the others but not see them...