Editor's note: Victoria Arbiter is CNN's royal commentator. Follow her on Twitter.
(CNN) -- The Queen has invited the Middleton Family to Sandringham for Christmas, or so the British newspaper headlines recently declared. Oh, that it were true if only because Richard Palmer, royal reporter for Britain's Daily Express, tweeted that if Carole Middleton, the mother of Catherine, the Duchess of Cambridge, emerged alongside the Queen and drove to church, he'd cartwheel naked down the path. Lucky for Richard -- and dare I say even luckier for us -- it's highly unlikely.
Invitations to Christmas are never extended to the families of royal spouses and why should they be? Nothing personal, simply that Christmas provides an opportunity for the Queen to enjoy quality time with her own immediate family with no expectation of being on parade.
Well, that and the issue of space. Large as Sandringham might be, it is a house, not a castle. When the whole family is in attendance, there just isn't room for anyone else.
The Royal Family has Christmas down to a science, and the Queen's festive plans are as reliable as television airings of "It's a Wonderful Life" and my inadvertently cooking the turkey upside down. It's the same every year.
Since the fire at Windsor Castle in 1992, the royal family has gathered to celebrate Christmas at Sandringham, the Queen's privately-owned Norfolk estate.
Following arrivals on Christmas Eve, afternoon tea is served. The evening brings a fancy black-tie dinner, and the opening of presents -- a German tradition embraced by Queen Victoria when she married Prince Albert.
After breakfast on Christmas morning, it's church, lunch, a huddle around the television to watch the Queen's Christmas message to the nation, a country walk, and an evening of parlor games. It is an occasion steeped in familiar tradition and protocol for the Windsors, but for the inexperienced newbie it's enough to make you want to double-spike your eggnog.
Sandringham is the Queen's house, and therefore as the Lady of the Manor invitations are at her discretion. She has consistently been open to change and has adapted to the times accordingly.
During her reign she has opened Buckingham Palace to the public, made the royal finances more transparent, made walkabouts the norm, signed the Commonwealth Charter, and she was the first reigning monarch to visit the Republic of Ireland since Irish independence. Christmas, however, is one area where change is unlikely.
The Queen is not obligated in any way to the extended families of either her children or her grandchildren. The Middletons may well be the grandparents of the future king, but so too were Earl Spencer and Frances Shand Kydd, yet that didn't see either of them swilling sherry and pulling crackers over the Queen's Christmas goose.
Were the Queen to invite the Middleton family, it would in turn pave the way for other in-laws to attend. Camilla's children haven't spent Christmas with their mother since she married Charles in 2005. Princesses Beatrice and Eugenie haven't celebrated Christmas with their mum since their parents' divorce in 1996. The list goes on and therein lies the quandary. Invite the Middletons, and suddenly Christmas becomes a free-for-all "plus one."
Last year, with the Queen's blessing, William and Kate chose to spend Christmas with Kate's family in Bucklebury, Berkshire. While alternating families for the holidays is the standard festive headache for us regular folk, it was an unprecedented decision for the Sandringham lot. By doing something different William and Kate effectively changed the model of a royal family Christmas.
The Queen and the Duke of Edinburgh enjoy a relaxed relationship with Michael and Carole Middleton. Before the royal wedding the Queen asked them to lunch at Windsor Castle.
In June 2012 they were invited to sail on the Elizabethan paddle steamer during the Diamond Jubilee River Pageant, and they joined other members of the royal family in the Queen's official carriage procession to Royal Ascot in 2011 and 2012. She has already publicly embraced the Middleton family far more than she has the family of any other royal spouse.
William and Kate are the new owners of Anmer Hall, a property on the Sandringham estate, but it is currently being renovated, so there's no room at the inn for the Middletons there. Even if it were ready, I don't see William and Kate leaving her family at home while they swan off to the "big house."
Every family celebrates Christmas in their own unique way, and the Middletons would never presume to be included in the royals' personal festivities, nor would the Queen, Philip, Charles and Camilla expect to load the corgis and a fruitcake into the Range Rover and head down to Bucklebury.
There is no slight, no malice, no scandal here, rather a wish to preserve the elements of sacred family Christmas. In that way, the royals are "just like us." Looks like Richard will be keeping his clothes on this year after all.
The opinions expressed in this commentary are solely those of Victoria Arbiter.