You posted this a year ago and I’m currently wondering the same thing about my chicken. I have a Starlight Green Egger, 10 weeks, and looks identical to your chicken. Did it turn out to be a roo?
My Starlight Green Egger, Buttercup, is 10 weeks old. I bought her from Tractor Supply and they were labeled as a “Premium Pullets, sexed chicks.” Since a chick she’s always been more aggressive and pecking at all the other hens. With the aggressive behavior and her comb growing larger/redder...