Do cockerels develop tail feathers differently than pullets? Reason I'm asking is that of my 5 SS, four have tail feathers growing and one does not. Maybe too early to tell?
I've noticed that roos often develop feathers much more slowly than pullets in some breeds- but not all.
If those were my Orps I'd say the one with the long tail was a pullet and the rest were cockerels. You'll have to band her and see if it works out that way!
ETA- Our posts crossed! This is a good example, then of a breed in which it doesn't indicate anything, because I'm certain you didn't get all boys. I think the one is likely just a pullet who is a bit slow. I think SS are fairly reliable to sex by color and vent.
Too early to tell, but males seem to have very round bodies with lots of white on the chest and stubby tails. Females in that breed get tail feathers much longer, much sooner.