I agree that she looks at least 8 weeks old. I think she is a JG though, as I have blue BA hens and they just aren't that burly. I was looking at JGs on Feather site and there is a picture "A lot of two-month-old Black Jersey Giant pullets" and from the photos I believe she would fit right in. My BAs are small, sleek and slender when compared to any of the other pullets I have their age. They also lay a small white egg. If naught else, once she starts laying you should know then, as I believe JGs lay brown eggs.