They're all the same age. The breeder said 7 weeks but I am not sure how accurate that is.... they're 95% feathered in...
Bird 2 and 3 look like pullets. Bird 1 cockerel
Nothing to do but wait! I had the same thing a few months ago. Usually the boys have a wider stance and look a little stockier, but still I had one that I couldn't sex until the 4 month! Good luck. I just gave a guess.