This is a response to the original post/bird in this thread.
This is really tough because except for the barred rock, you don't know what else for sure is in it. If the other parent is an Orpington, it could still be a pullet (otherwise, I think it's a cockerel). I just got into English Orpingtons, and they are even harder to sex than hatchery Orps because they grow slowly but are huge. I have a 3.5 month old pullet that I went back and forth and back and forth about a zillion times, because she has a big comb and wattles--but not as big as her brothers' combs/wattles, and she is nowhere NEAR the size of her brothers, which at 3.5 months are as large as my biggest mature Buff Orp hatchery hens (and I have some big, wide girls!). I decided this one English Orp is just kind of a "tomboy" pullet, and I have had other mature Orp hens with combs and wattles that would put a roo's to shame.