I agree, it is definentally broody. I would NOT let her "set" her imaginary eggs. I usually have between 3 and 10 broody hens at a time, and i take them out of the boxes. This is because i noticed that when they sit for a long peroid of time, (1-3 weeks) they loose wieght. they will become dazed-like and may be aggresive! They are very protective mothers!