What is my breed? Do they make a bantam jersey giant?

[Rena9]

So, this chicken came to me as a birthday present from my sister who was told it would be a "great egg layer". The other chick turned out to be a jersey giant male living up to their size reputation. This one though, she's little. Smaller than my RIR hens at almost 6 months old. Her feet are yellow just like her broodmate. Any idea on breed? The second to the last pic is her with my son (don't worry, we practice good post-chicken hygiene) and the last is the 23 of sept when they were still little

 

[red horse ranch]

The black chicken appears to be an Australorp. They have iridescent black feathers that look green in the sunlight and black legs. It is a female and if this is what she is she will be a great layer.

 

[Brahma Chicken5000]

She’s a Jersey Giant pullet. Possibly younger than you think.

 

[Alexandra33]

Yellow foot bottoms indicate Jersey Giant, therefore, yours is indeed aforementioned breed. She could just be developing a little more slowly than the other.

~Alex