OK, well Ameraucanas I have a tiny bit of experience with. I raised 5 Lavenders over the winter. By 13 weeks, there was one I was positive was a male and I sold him. I never heard back any different, so I think I was right. There was another one I was iffy on at that point, but a hawk killed him before I was positive, but I think that one was male too. It was 15 weeks old. There were still two that I thought by combs were males, so at 16 weeks I sent photos to the breeder, and he told me I had three nice pullets. So really, for all I know, the one the hawk killed could also have been a pullet, since I had been going back and forth on that one too. I obviously couldn't tell by comb, or even by feathers, as late as 16 weeks. But as soon as the breeder told me the three were pullets, then I could see it in their tails, and body shape, and stopped second guessing myself.Any new pics of Corabeth? I'm good at sexing other people's chickens LOL! Limabean's chicks are blue ameraucanas. They are so cute, but I'm afraid they are all roos.
It's funny, I was kind of like you, because I thought I had ALL roos. I think part of my problem was that they all looked the SAME, for the most part. If I would have kept the two males longer, until there were more obvious differences, then I would have had more signs to go by. But it is also possible I had ALL pullets, and that's why I was obsessing over every tiny little difference, because there really wasn't any real difference. Except for the first male getting a pinker comb at a younger age. I found that going by the "three lines" of the comb was not right. They all have three lines. They are just harder to see on the pullets, but since they were there, that's why I thought all my pullets were roos.
But anyway, do you have photos of them? Have you asked on the Ameraucana thread yet?
Now as to my Corabeth, I don't know if I can use what I learned with my Ameraucanas or not, since she is not pure Ameraucana. But since you said you are good at telling with other people's chickens, I did try to get some pics for you. They are not the best, but here goes. (She is 15 1/2 weeks old.)
The wind probably messed her feathers up, and of course, she knew I was going for her, so she went into the wire pen and wouldn't come out. Then my camera battery was dying, so I decided to try again later. If I need to, I can post more when I do that.