My 1+ y.o. hen laid a gray mini egg today?

[NHchicks]

I've never seen this before. My RIR laid an egg about half the size of their regular brown eggs, and it was grayish.

I don't think I'm going to try eating this one.

Does anyone have any clues what this is about? Maybe she's going to molt and her egg producing hormones are winding down for a while?

I just took a picture, compared to a usual egg.

Another idea that just came is that maybe one of the 4+ month old chicks laid this egg? I didn't see any around the nest, but I suppose it's possible. Don't EE's lay blueish eggs? My rooster may have had a tad EE in him. I don't even know. I'm so confused.

Edit: Oh wait a minute. I just looked at the sticky post on first egg pics, and sure enough, this egg looks like an Americaunus (or however you spell that) and I think that's what the rooster was a mix of. So one of my pullets just started laying. And I'll be getting blueish eggs. Wow. I hope they end up bigger than this first one, tho! The Ameriwhatevers must start laying earlier than my RIR/NHR hens, because this pullet is only 4 mo. 1 week, while my older RIR/NHR hens were a full six months before they started laying.

I'm talking to myself here, but you all helped me anyway.

Thank you!