This one? I vote cockerel. Too much comb for a pullet. Blues cockerels are easy to tell when they start getting new feathers on their hackle, cape, saddle and the bow of their wing. The feathers are black and stand out even on a dark blue bird. Because they are so black and shiny against the duller blue older feathers, they show off their narrowness and pointedness more obviously and earlier than your black or splash birds' feathers will. Part the feathers and look at the new ones coming in on the saddle area. A single feather of a blue cockerel will be obvious.
Oh yes, that one is for sure a cockerel, it's the blue that is leaving everyone debating. I'll keep an eye out on the feathering!