Perhaps your Christmas cards from the House of Windsor are still stuck at the post office. But those who have already received theirs report that Prince Andrew and his ex-wife Fergie have underlined their confounding, continuing partnership with a joint family holiday greeting. The card, which features the York rose on the front and, inside, a photo of Princesses Beatrice, 11, and Eugenie, 9, comes with a message from “all of us.” Prince Charles, meanwhile, has chosen a relaxed shot of him and his sons said to have been taken by a police bodyguard during an interlude in a polo match in the English countryside. The photo has Charles (in jodhpurs, a blue-checked shirt and tan riding boots) with his arms draped over the shoulders of his grinning sons, William, 17, and Harry, 15. Taken on a bright summer’s day, it shows Wills apparently squinting because of the sunshine in his eyes — while Harry looks directly into the lens.