HARRY AND MEGHAN

A royal Christmas.

DOES ANYTHING about being a trainee royal throw Meghan Markle? The actress, 36, glided effortlessly from Suits to the role of fiancée to Prince Harry, 33, whom she’ll wed in Windsor Castle on May 18. Already she waves to crowds as if born to do it, and deftly handled her first BBC interview.

Now the real test: can she handle Christmas with her future in-laws? This year, Meghan will join the Queen at Sandingham House, the Windsor retreat in rural Norfolk. The Los

Angeles native will attend services with the family at the Church of St Mary Magdalene, then join them for lunch on the estate.

It’s the first time a partner of a “senior royal” has ever scored the invite, which shows how far the royal clan has come since the last time one of their number fell for a divorced American (that would be Edward VIII and Wallis Simpson, which ended in his 1936 abdication). “They are much more enlightened now,” says a family friend. “It is time to get on with life and not be stiff and stuck in oldfashioned rules.”

It all may be less about what the Queen decrees than what her beloved grandson desires. “With Harry, protocol goes out of the window,” says royal writer Hugo Vickers. “He does his own thing!” And so he shall, staying with Meghan at Anmer Hall, a nearby Georgian country house, where they’ll be joined by Prince William, Catherine Duchess of Cambridge, and their children. Meghan is expected to take part in the Windsor tradition of exchanging cheap gifts (During her first royal Christmas, Kate gave the Queen a jar of homemade chutney). But the animal lover is free to take a pass on the Boxing Day pheasant shoot, says author Ingrid Seward: “She can always stay at home with the kids.” The visit isn’t likely to trip up Meghan, who recently spent an hour schmoozing employees at the Windsor Castle Christmas party. Naturally, “she was a hit,” says the palace insider. As another Windsor partygoer put it, the capable newcomer is “charm personified.”

“Things move on, but [Harry] gets away with a lot more than most!” —A palace insider

“Its nice that she’s going to Sandringham,” says royal expert Hugo Vickers. “Having a star in their midst is rather nice.” Harry & Meghan

The royal family “have been a solid support and my grandparents, as well, have been wonderful,” said Harry (with Meghan on Dec. 1).

Why is the Queen OK with Harry’s fast courtship? “It’s her age,” says Ingrid Seward. “She’s easier going [at 91].”