Is It A Bantam Chicken?

[BlackRock13]

Q-Is it a bantam chicken?
She is about 22 weeks and is smaller then my other chickens and my rooster is a bantam and always walks with her.

(She is a cute BSL but instead of making chicken sounds, she sounds like a ship horn..)

 

[Wyandottes7]

She doesn't look like a bantam to me. As far as I know, Black Sex-Links only come in large fowl (well, they can be created in bantam size, but I don't think hatcheries sell them).