I would deal with her the same way that I would deal with a ROO that chose to challenge me. I wrote about this in my Coop Project Thread...here is a quick answer.
She has adopted the position of Flock Boss and is pecking you to show that SHE is in charge of the flock. If she was attacking you it would because she sees you as a "threat" to the flock. So essentially she's just letting you know in "chicken speak" that you are below her in the "pecking order."
That is actually great...because if she saw you as a threat and was attacking you, that would be a long row to hoe. In the end she may wind up as a center piece to a meal or be taken to another home where she would most likely wind up being the center piece of their meal.
To begin: YOU need to SHOW her that YOU are in charge...by treating her the way a ROO would treat her.
When she approaches you to give you a peck, take your hand and press her to the ground...hold her firmly, don't hurt her; and she will struggle.
Hold till she settles down, then , while still holding her use your other hand to mess with her hackles and her tail. Then let her up, but be ready. If she accepts you as the "ROO" of the flock, she'll ruffle her feathers and walk away with an indignant strut. If she does this then wait a minute or so then give her a treat to reinforce that YOU are also the provider.
With my flock I make a habit of periodically pressing hens, to avoid being part of the pecking order. They stand and ruffle their feathers and walk away indignantly.
You will also notice that at times your hens will squat and stomp their feet in front of you...don't ignore this behavior. This is an important part of their socialization within the flock. Gently put your hand on the hen's back, mess with the hackles followed by her tail and she will be happy. She is using Chicken Speak to recognize you as the ROO of the flock...it's a good thing.
If she doesn't accept you, she will try to peck you. Thus the battle of position begins. Be PATIENT and do not get frustrated, chickens are not Rocket Scientists...they can be slooooww to learn.
Repeat the procedure until she shows signs that she accepts you as the "ROO".
Hopefully you will have caught this in time, the longer this goes on...the less likely the behavior will stop. Chickens are hardwired, once they LEARN something, it's hard to re-educate them.
My little Flock Boss, doesn't peck me....No...she pecks any chicken that gets remotely close to me. She's a Silly Jealous Bird.
Edited by Rock Home Isle - 5/6/16 at 3:01pm