Wow, they grow fast. I don't know what gender. I picked up a D'Uccle last Thursday that turns one week old tomorrow. I only brought one home and I'm hoping for a pullet. They all looked the same in the bin.lol
I'm going to guess pullet. That is only based on the fact that I have a 3 week old in my brooder that I ordered from MPC that is supposed to be a Roo, and his comb is bigger than that already.
That my dear is a ROOSTER! I would bet money on it. Hens don't have any comb for months, and that little boy has a decent sized one and he isn't even feathered out yet!
That looks a lot like a hen to me. I had d'uccles for several years and the roos always had much redder combs than that. I might be proved wrong but im saying hen.