My hen was very sick and has been moved into a stall away from the rest of my flock. She has been away from them for over a month and now that she is well I tried to put her back in the chicken yard with the other 15 and they all went after her. I immediately took her out and put her back in the stall. How do I re-introduce her to the flock without getting her killed by them? Any advice will be much appreciated!