Yeah, that's all girl. Just look at those hips! She might be hiding her eggs under those poofy feathers. Have you checked?

I had a funny conversation with one of my partners about how the first California White to get bright red comb/wattles/face was/wasn't a rooster. "So ... where do you think this egg came from? Hmmmm?" He kept putting her in the cockerel coop, and we kept finding eggs in the corner, which he insisted were laid by some other undefined bird who was sneaking in just to lay, and he wouldn't budge until the other California Whites caught up with the precocious one about a week later. Just to push the irony, once the hen in question was put in with the other layers she insisted on escaping the run every day to to lay her egg in the corner of the cockerel coop. They are creatures of habit.
Had the same conversation in reverse with the same person about a BA cockerel. We were standing outside and I noticed one of the sexed BA "pullets" was shimmering in the sunlight and getting pointy feathers in appropriate places. Me: "Ohhhh! It's a boy!" Him: "No. That's definitely a she." He wouldn't believe me until it crowed. Me: "Is that her egg song then?"
I usually take egg laying or crowing as definitive proof of gender.