From reading their website, I see two options.
Zombie, which are a fibro breed that are usually white spotted black, but I am sure they are variable enough to include a hen marked like yours.
Fribro Easter egger seems less likely because the bird shows no traits of a traditional EE. No beard, no pea comb. But it is possible.
Based on her coloring, I think she is more likely to be the Fibro Easter Egger.
The Zombies in the pictures have a lot more white, and the text says they have a White Leghorn mother. This gives them the Dominant White gene, which turns black to white except for some bits of leakage. I'm pretty sure OP's bird does not have that gene, based on the amount of black she is showing. She has a different set of genes.
Regarding the appearance of the Fibro EEs, Meyer does have one picture of a male with a single comb, and the text says they may have crests. This suggests some Cream Legbar in the mix. A cross of Cream Legbar and Ayam Cemani, with the offspring interbred for a generation or two, could easily end up with some hens that look like the one OP has. If Meyer's flock also has Ameraucana in the mix (or the kind of Easter Eggers that resemble Ameraucanas), that would explain the pea combs and beards on some of the other birds in Meyers' photos.
Of course if she lays blue or green eggs, it will be obvious that she is an Easter Egger. If she lays white or cream eggs, then she is either one of the Easter Eggers that fail to lay colored eggs, or she is a Zombie, or else the Ayam Cemani breeding pen is throwing some off-color birds (may be possible, if some of them are carrying some genes that are recessive to the ones that make the correct coloring.)
Ordered 10 Ayam Cemani (already had an adult breeding group) from Meyer last year. They were sexed, day-old females. Except one wasn't black as she matured. Then this year, we ordered another batch and got ANOTHER of whatever that breed is. Hmong? Maybe?
Have you tried asking Meyer? If their Ayam Cemani pen is throwing off-color birds, they probably want to know about it. Or if this is a different kind of chick, put in your order through carelessness or by deliberate substitution, they may be able to tell you that (and maybe avoid that problem for people who order in the future.)
I don't see any Hmong on Meyer's website. If they are starting to raise that breed, they might hatch to build their own flock but send out a few chicks here and there as substitutions or extras, without listing the breed on the website yet. So I can't completely rule it out, but I think it is not very likely.
