Our two cats hang out with our chickens all the time. They even go into the hen house to catch the mice in there. They haven't hurt a chicken yet. One evening, without our knowing, the hen house door was closed with all the chickens outside. When we went out after dark to shut them in, they were all huddled together outside, scared in the dark. The cat was sitting nearby, keeping an eye on them. If she had wanted a chicken dinner, she could have easily had it at that point.
She doesn't hurt the babies or the hens. And she catches mice and rats daily. I don't consider the cats a threat to my chickens.