We have 5 chickens. When one of our rhode island reds came down with gleet vent we brought her indoors to care for her. When the weather gets a little milder here in Wisconsin, we would like to return her to her flock. She's back to good health and I took her out yesterday to see how our other girls would react. One of our girls attacked her. How do I safely reintroduce her to the flock?