It must be a BO thing. I have 2 BO hens and 4 RIR hens. The BO's chatter all day long, and the RIR's sit there and listen to it!
I agree with the post above too - make sure she has some chicken friends to hang out with. Chickens are very social and like company. If she is lonely for friends, she will seek you out - constantly!
Does she get to free-range? The more space she has, the more things she will find to do.
You could also try and find things to keep her entertained - and they don't have to be super expensive either. A pile of leaves to fluff around in can keep a chicken busy for hours. A stack of bricks to climb. A fallen tree branch she can meander through. A bale of straw or hay to pull apart and spread for miles
My BigMama was a grumbling bossy girl, must be a BuffOrp thing!
Great advice above. Ice blocks with goodies inside are a great hot weather thing and at this time of year all surplus fruits and veggies go to the birds! I give them stuff like squash, and apples whole it gives them something to do and bicker over, bossy ladies love to bicker