can you tell me what is my chickens

Can you get a closer picture?

Are the legs slate / dark? Single comb?

Looks like an australorp.

 

Could be an australorp, but it also sort of looks like a Sumatra. Closer pics would help a lot!

 

She looks like a Sumatra mix.

 

I wouldn't say Sumatra unless she has has dark face skin... Australorps, hatchery grade ones at least, tend to be very lean until they're older & fill out.

 

She does have dark face skin. She is obviously not a purebred, but I think she does have some Sumatra in her.

 

I agree with BantamLover55,
She looks like a sumatra cross.

If you click on the picture it will in large it and you can see that she has a black face.

 

Looks like a Sumatra mix to me, too.