What breed she is?

[drumstick diva]

ayam cemani cross- very pretty girl

 

[Better Than Rubies]

I'm not a chicken expert, either, but her color actually reminds me, personally, as more of the Australorp's black. And in the pictures, she doesn't look bantam-sized...not exactly, in my opinion. But her owner would know, I'm sure!
And I didn't think of the Sumatra, either, but she doesn't have the pea comb... Just saying, lol.

 

[suntonova]

There are at least 2 different chicken breeds that are all black, inside and out. The svart hona is from Sweden and the ayam cemani is from Indonesia. You can find both throughout the United States.
Both breeds lay cream to light brown colored eggs. The black egg pictures found online are dyed or painted, or the image has been manipulated. The black skin is from a gene mutation that causes fibromelanosis, an excess of melanin production. This is also found in silkies. This gene does not impact egg color.
Both the svart hona and the ayam cemani have little oddities that will pop up occasionally. I've talked to breeders that have had feathered feet pop up in both. I have a feather-legged ayam cemani rooster in my mix coop right now. Breeders do not consider this a desirable trait and will normally remove a feather footed bird from their breeding stock. It would not be absurd for someone to get rid of the chicken and just label it a barnyard mix. It would not be worth any more than any other pretty pullet.
As far as price of a breeding quality hen, the prices have decreased considerably. Every year since they've been imported, they increase in number exponentially. The svart lays about as well as any other typical chicken and has a good hatch rate. I average about 2 eggs every three days. I get about a 90% hatch rate in a normal hatch. The chicks usually do well. This is also technically a land race. This means that cosmetic abnormalities, while not preferred, are not uncommon and are not disqualifications that require culling. What matters is whether the bird is hearty and healthy. Most breeders in the U.S. do breed with a preference toward clean legged, single combed birds with no color leakage. It's not unusual to find backyard flock owners selling their chicks for around $20 each in some areas.
The ayam cemani is among the poorest laying chickens. They only lay about an average of 80-90 eggs per year. They are also quite delicate as chicks and will have a high mortality rate if not perfectly tended. They are very small and slow growing. I had gotten an ayam cemani chick and a cream legbar born in the same hatch. The cemani chick was only half the size of the legbar at 2 weeks old. Breeders will typically cull with a very heavy hand. Many will regularly only determine 10% of a hatch worthy of growing out. Therefore, their prices aren't coming down as quickly, but they rarely cost in the thousands any more. It can still be hard to find them.
The hens of both breeds are quite petite. A visiting vet actually listed one of my hens as, "black bantam," in her file. They're not actually bantams. But, if you're used to seeing the typical dual purpose chickens you buy from the feed stores, the mistake is understandable.

 

[theoldchick]

Here's some more information about the Svart Hona:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0ahUKEwj__Y3s8_zXAhVMOiYKHXoeDZMQFghLMAQ&url=http://greendaleheritagefarm.com/products/svart-hona-or-swedish-black-hen/&usg=AOvVaw0T78tnK2u1IEQ9nXfeXJdI

https://www.google.com/url?sa=t&rct...ack_hen.html&usg=AOvVaw3HAWZ14UIakEE21MTKjVDP