I added (14) two day old heritage Buff Orpingtons to my small flock and looked for information all over to help me figure out how many roos and how many pullets I had. Now 20 weeks old, I can tell you the advice that was spot on: cockerels (roos) have thicker legs, they stand more upright as their center of balance is different than pullets, and they'll develop those red combs and waddles usually, but not always early on. Pullets have daintier legs, hold themselves more horizontal, and are slower to develop combs and waddles. My pullets were hiding behind their brothers and letting them test/ see/ try nearly everything before checking it out themselves.
Testing by wings, etc early on was not accurate for me.
That said, I'm seeing pullets.

It looks like you have better odds than I did! We ended up with 8 cockerels and 4 pullets.

