I’ve had little cockerels that I could tell were male within 2 weeks, but usually you will see the comb really pop around 3-4 weeks. Some can be slow to develop though, depending on the rest of the flock. I usually find a dominant male will show himself quickly, while more shy boys may be slow.
I’ve got a few groups of young ones now, I’m just getting a feel for genders. One hen has 4 chicks, and I’m pretty sure 3 are males

but a good portion of the other chicks are looking female.
I think all 5 of these might be girls, 4 are silkied.
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This is Carrie with her 3 boys.
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