I think like any big family, some are closer than others. I have some cousins I am closer to than others, based on age, proximity, and personality/mutual interests. I agree that William seems close to Zara and Peter, and it is clear from public appearances like the jubilee concert and the walk to church on Christmas that their kids know each other well and William and Kate's kids are comfortable with Zara and Mike and vice versa. Zara seems to be on good terms with everyone, always photographed hugging and laughing and being affectionate with them all (including her uncle, the king!). (Side note, I have always thought that if I could be a member of the royal family, I would like to be Zara ... close enough to get invited to all the good parties, rich enough to live comfortably, but far enough that you don't have to deal with the protocol and the responsibility.) Beatrice and Eugenie (their children are still babies/toddlers), and particularly Edward's kids Louise and James, are a bit younger and so it's understandable they wouldn't be as close. I also was struck by all of the grandchildren (William and Harry, Zara and Peter, Beatrice and Eugenie, Louise and James) during both Philip and QEII's funerals and surrounding events, they were clearly grief stricken (I think of the images of when some of them came out from Balmoral to see the floral tributes a couple of days after the queen died, and they had all clearly been crying), mourning their grandparents, not just going through the motions in public.