Broody hens are very distinctive. She will have a "Cluck, Cluck, Cluck" sound when she's walking around. Also, she'll sit in the nest, eggs or not. When fully broody, most hens will protest and try to peck or bite you if you try to remove them from the next as well as fluffing their feathers out to make them look larger than they are. They even make growling noises. If she's not displaying any of these signs, she's most likely just getting used to her new surroundings, as well as letting the others know she intends to be the queen bee.