My coop is 8x9, I have 4 hens and 3 pullets (6 months old), one of my hens just hatched chicks last week and I can tell you that none of the other ladies are allowed within 3-4 feet of her chicks or she goes on an all-out assault. IMO I don't think you have enough room for her to hatch chicks in that coop. Could you come up with another area where she could have some space?