This is a story about Pip.
I ordered 3 Bielefelder pullets (and 1 Blue Australorp pullet) from Mt. Healthy. I received 4 Bielefelders and one 1 Blue Australorp. All healthy, happy chicks.
My reason for ordering Biels is because they are sexable at hatch. The pullets have the chipmunk striping, the cockerels are blond with a white headspot. So there should be no problem with sexing them, and the Blue would have been the 90% accurate vent sex.
Picture of the 4 Biels.
Yes, very obviously females. Pip is probably the one facing to the right; she's always been smaller than the rest.
A few weeks ago, I saw a thread about how Mt Healthy mis-sexed a lot of their birds this spring. Nope, not mine; they're sexable at hatch. (I'm confident that the Blue Australorp is a pullet, and she's not part of this story. Sorry, Button. Your story will be told soon.)
I posted this picture of Pip.
Pip at 5 weeks. And someone said, that's a boy. 100%. That comb, beginnings of wattles, no doubt.

But... but... sexable at hatch...
But... but... if it's the "extra" chick, it might not be a Bielefelder. How many breeds have the chipmunk look as chicks, male
and female? Uh... several.
Someone else quoted Mt Healthy as saying that any extras would be the breed and gender you ordered. No, I didn't verify this. Because now it means nothing, really. Pip is what Pip is.
Someone else said, not so fast. Pip has skinny little pullet legs, so there's hope.
The next day, Pip tidbits a bug for one of the other girls. Can I hang my hope on skinny legs?
Pip at 6 weeks. The legs are still skinny, anyway...
Pip about 4 days later.
I didn't get a good picture today. I'll try tomorrow. They're 7 weeks old now.
But I am feeling better about Pip being a Bielefelder pullet. The other three have combs about the same size, so maybe Pip's popped early.
And they all have skinny legs.