Sudden Aggression in hens

I don't know what is up with my chickens this morning. Whenever I go to the run door, my big New Hampshire runs up to me, squats down, broadens her shoulders and wriggles her butt. I've been expecting her first egg for about a month now. She's 6 months old. (none of my three 6 monthers has laid an egg yet). When I walk away, she resumes being a normal chicken. I picked her up one time. She has never been an aggressive bird, always sweet, and was this time too until I set her back down. She and my RIR got into a viscious fight. I grabbed the RIR, who had in that 2 seconds, ripped the comb of the NH, and drew blood from her face. Both birds were flying at each other with beaks and feet. I got a 4 inch gash on my hand, not sure who inflicted it. I've seen the RIR aggressive in the past, but always just posturing, and maybe bumping someone with her chest. Not out for blood like the 2 are today.

Unlike the NH, my RIR usually does not like to be held, but she calmed down when I got her out of there. I took her inside and she sat calmly on my lap. One of my cats even came over, jumped on my lap too, and the 2 just sat there one on each knee for about 20 minutes! Then I went back out to the run, and the NH launched herself at the RIR as soon as I opened the run, even though I was still holding her! She wants revenge for her bloodied face! I took the RIR back out. Every time I try and take her back to the run, she freaks out before I even get the door open, and the NH is there waiting to get revenge. Luckily we have a second tractor that was empty at the time, so I put the RIR in it. Then I grabbed one of my other hens and tossed her in there with my RIR, and they seem to be getting along just fine.

Should I keep the RIR and NH separate from now on? My 9 birds always appeared to get along just fine prior to this.