Well I now know for sure that Pedro is the reason for the discord amongst the flock. This morning she was in the process of laying when I let them out and I decided I'd go ahead and give the others their get out of bed snack and keep back Pedro's portion for when she had finished laying. Well the difference in the flocks behaviour was large, no one chased no one, each just got on eating their treats and not bothered by nor taking any notice of the others. The flock were peaceful and getting along great, even Roo who usually gets chased off, was feeding along side them and no one bothered her at all. When Pedro came out I gave her, her share of the treats, the others came over but I helped hold them back so she could eat her share, Lilah however helped herself to some of Pedro's treats but Pedro didn't show any signs of being bothered about it. A while later I put out some bird seed and spread it around so everyone could get some and what a difference there was! Squabbling, chasing and the usual discord and as usual Pedro instigated it. However, I understand it, before Lilah and Roo came, Pedro was head hen and when Lilah came she took over, and shortly after this, Jellybean had a go at toppling Pedro although she didn't succeed, then with Roo growing bigger by the day, Pedro is having to reiterate that she is second in command and I believe is acting the way she does to ensure no one else over takes her and her doing so sets off the others and it is evident that all are working to ensure they don't lose their ranking in the flocks.
I admit though, it was lovely to be able to watch them all getting along but I never be without any if them so they just got to work it out for themselves - flock life