As an age-old institution, the British royal family is steeped in strange traditions and odd rituals. Some of them we're familiar with, such as the Queen giving a speech on Christmas day each year, and others we're less aware of - for instance, the practice of keeping six ravens at the Tower of London at all times.
Meghan Markle, as one of the most recent additions to the family, has obviously not experienced all of these traditions yet - but she's about to, as this year she'll enjoy Christmas with her new in-laws.
The Duchess of Sussex did actually celebrate the festivities with her then-fiance, Prince Harry, in 2017, but this year her mother, Doria Ragland, will be coming along to Sandringham as well... and both of them will be weighed by the queen.
As part of a tradition that dates back to King Edward VII's reign in the early 1900s, her majesty the Queen requires all her guests to step on a pair of antique scales when they first arrive for dinner. Then, after a (no doubt extravagantly luxurious) meal is enjoyed, the members of the "royal clan" are asked to step on the scales again - supposedly to make sure that everyone has been well fed throughout the day.
There are a number of other rules that must be adhered to on the day, too.
Guests are expected to enter the dining room in order of seniority (meaning the Queen will be first, and, presumably, Doria will be last), and everyone is invited to wear a paper hat while they eat. The Queen is excused from this tradition, however - perhaps because she much prefers wearing her actual crown.
Breaking away from tradition, though, this is one of the few times that a non-royal has been invited to Christmas dinner, and the first time that an in-law has been asked to take part.
Ingrid Seward, a royal biographer and commentator, spoke to Grazia about the royals' decision to invite Meghan's mother to the occasion. "It is unusual for an outsider to be invited, but the royal family does change," she said. "I’m sure the royals will do everything in their power to make Doria feel at home."
Doria is set for a real treat on Christmas day, too, as the family always have a full roast dinner plus an afternoon tea. They also reportedly take a walk around the royal grounds between meals, just so they can "make room" for the copious amounts of food they'll be consuming.
As embarrassing as it may be to weigh oneself in front of a room full of other people, then, it seems like it's probably all worth it for the fancy royal dinner that follows.
Still, it's probably not good etiquette to loosen your jeans or take a nap on the couch after scoffing down several plates of turkey and potatoes, so there are still some downsides to dining with the queen.
So, enjoy your weigh-in, Meghan and Doria - if you need us, we'll be telling bad cracker jokes and getting drunk on port. Merry Christmas!