I think my 6-7 week old olive egger might be Roo, I know it's still kind of early to tell but wanted to get the opinion of someone with better trained eyes! Haha
I would say post some pics of some of your other birds too. The feather pattern on your OE says female, but the size and color of the comb suggests male. That one will need a few more weeks to nail down, but I'm leaning pullet.
It's the only OE I got, but its comb is way more developed than the others (silkies, ameraucanas, d'uccles). Its bigger than the other birds also and a bit more aggressive