That appears to be an Easter Egger; a blue egg laying chicken that does not meet the standard for any breed. They are usually part Ameraucana. Ameraucanas can only be one of eight colors, so an Ameraucana that is not one of those eight colors is an Easter Egger.
right, i wrote ameraucana x ? i should've typed ameraucana crossed with what. sorry about that. i would like to make a cross that looks like this one day, i have no idea which breeds were used. i was just hoping someone would know, it's really pretty.
EEs come in any color you can imagine. Some have cheek muffs, some dont. Basically, it is any mutt chicken that has a blue egg laying breed in it's background like an auracana or an ameraucana giving it the ability to lay a blue or green egg. I had one that looked very similar to that. Her name was Clover.
So yes, you are right, she is probably an ameraucana x, but with what else? Who knows...most EEs come out with the muffed trait.
Ah, I misread. Nobody really knows the secret Easter Egger formula that hatcheries use, but I've seen plenty of photos of similar looking hatchery EEs, so, as Donrae said, if you order a few you're sure to end up with one eventually