This looks like a boy to me, but it's still too young to be certain.
Thank you for responding. I'm becoming increasingly confident that this one IS a cockerel, along with the smallest of my three Silkies, leaving me with one female. My two "suspects" each have a walnut comb forming, and waddles, one with red coloring and the other a dark grey. My third chick has neither of these features. It's not just their appearance leading me to that conclusion, but also their behaviors and the behaviors of my other chicks in the mixed flock. Nobody bats and eye when I handle one of the "suspicious" chicks, but as soon as I pick up the alleged pullet then both the Silkie suspects and my Barred Rock cockerel stand at attention and observe me with profound interest, if not concern.
My Gingy, presumed cockerel, at 7 weeks:
My second suspected cockerel, Tika:
And my potential pullet, Didi:
I know these photos aren't great, and I apologize for that, but I'm fairly confident in my assessment so far.....at least until a presumed cockerel lays an egg.