Barred Rock pullet or roo?

[BlazeJester]

I have yet to have a barred rock pullet (hatchery, of course) that I didn't freak out about at some time or another. Goes with the breed

 

[En Plein Air Farms]

Until they reach egg laying age (several months down the road for yours) they know they aren't ready for mating behavior and will generally have a fit when the rooster tries it.

 

[donrae]

One of my adult barred rock girls sparred with my bantam roo through the fence consistently for several days. His pen was out in the pasture, she was free ranged, she would come over and start stuff with him, fluffing those neck feathers out and just flying at him with those claws out!
You bird still looks like a pullet. continue to post pics as she grows if you want, it's good reassurance.