I'm no expert, but I say pullet. My BO rooster at a little over 4 months has saddle feathers, tail feathers, and now crows. He's a big, brawny thing too. He'll be 5 months at the end of the month.
X2
I would say pullet as well.
At 5 months my cockerel was crowing, broad chested, thick legs, had the saddle/tail feathers and was quite large compared to anything around.