Just keep in mind that even if you remove her (whether temporarily or permanently), with the next batch of chicks, the bird that's the bottom of the pecking order (or another low ranked bird) may exhibit some of the same behavior. It's just how it goes, every batch of chicks I integrate gets pestered by one of the lowest ranked birds. I've never had to separate but I also tend to not interfere, as I expect the chicks to learn to run for safety and to stay away from the bully.That's the sort of thing I'm worried about. If it's always going to be a problem everytime I hatch or buy chicks it might be best to remove her from the flock. I also wouldn't want to hatch chicks from an aggressive hen, just as I wouldn't from a rooster.