Right, exactly! To be honest, I think the Queen has been mostly close to Princess Alexandra, courteous and friendly to Prince Edward, Duke of Kent. I do not believe the Queen was ever very close to Prince Michael of Kent since he was so much younger. And indeed, Prince Michael's choice of bride was problematic. And personally, Princess Michael seems to have never been especially well-liked among senior royals.
Reportedly, none of the senior royals are invited to Lady Gabriella's wedding. Neither did they attend her brother's wedding. And they were not invited to either of the Wales brothers' royal weddings. Although, out of courtesy, their parents, Prince and Princess Michael of Kent were invited to the weddings of the Wales brothers. Pippa Middleton is invited to Lady Gabriella's wedding on May 18th, since the bridegroom is a former boyfriend of Pippa's. Lady Gabriella and her fiance were invited to attend Princess Eugenie's recent wedding, and I suppose Freddie and his wife were there too since their daughter was in the bridal party.
However, it's not unusual for parents' and/or grandparents' cousins to be known to their offspring, particularly if they all live in the same town and get together for family reunions. Living in the same town though is generally a rare occurrence for most large extended families in this day and age. The royals are a bit different though than most families. While I wouldn't expect extended cousins who are not first cousins to be particularly close, in the royal family, they do all know each other fairly well. And the British royal extended families do mostly all join the Queen for annual Christmas lunch in December.