Before getting married, Harry brought Meghan to the Queen's holiday festivities.
Royal protocol dictates that only spouses of royals can attend the queen's festivities at her private estate in Norfolk, according to INSIDER's Talia Lakritz. Even Kate Middleton wasn't allowed to spend Christmas with the royal family in 2010.
Prince Harry reportedly asked the queen to make an exception, and Meghan became the first royal fiancée to spend Christmas with the royal family.
Meghan is the first mixed-race divorcee to marry into the royal family.
"It was deemed a royal union fit for the twenty-first century and a turning point for the monarchy," royal biographer Katie Nicholl wrote in her new book, "Harry and Meghan: Life, Loss, and Love." "Meghan was the first mixed-race divorcee to marry into the royal family, something that, decades ago, would have been unthinkable."
Her marriage to Prince Harry also marks the first time a royal family member had a church wedding with a divorcee.
The couple married in May, an unlucky month per royal superstition.
Since the age of Queen Victoria, it's been a superstition that it's unlucky for British royals to get married in May, but Meghan and Harry were one of the few royal couples to do so, tying the knot on May 19, 2018, according to Claire Nowak of Reader's Digest.
The couple had a modern wedding that broke a number of royal traditions.
The wedding ceremony marked a "turning point for the monarchy," according to Nicholl, in part because of its multicultural elements. "Complete with a gospel choir and an African American bishop, the ceremony was a departure from tradition and captured the imagination of the world," she wrote.
At the reception, the couple opted for untraditional wedding details. Traditionally, most royal wedding cakes are fruitcakes, but Harry and Meghan had a spring-inspired lemon and elderflower cake coated in buttercream and fresh flowers, according to Moody.
And instead of using a Royal Warrant holder — go-to businesses for the royal family — for their floral arrangements, they chose London-based florist Philippa Craddock, reported Nowak.
Prince Harry wears a wedding band, whereas the rest of the royal men don't.
Prince Philip and Prince William don't wear wedding bands, and Prince Charles wears a signet ring on his pinkie, according to Moody. However, Meghan and Harry exchanged rings, signifying equality in the marriage and modernity for the monarchy, says Meghan McKenna of Fashion Magazine.
Meghan and Harry are more affectionate in public than other royal couples.
Tim Rooke, Shutterstock's royal photographer, who has photographed the royals for more than 25 years, told INSIDER Meghan and Harry are the most affectionate couple he has photographed.
"Compared to Kate and William, they are much more affectionate in public which could be attributed to the different pressures placed on William as the next in line to become king," he said. "We don't often see Prince William and the Duchess holding hands, but the Sussexes do it if cameras are there or not."
They're also more vocal than other royals.
According to Nowak, royal families don't typically open up about their relationships until they're engaged and married, but Markle expressed her love for Harry early on in a Vanity Fair interview. Harry also issued a statement through Kensington Palace to the press for harassing Meghan, Nowak said.
And while the Queen and the rest of the royal family avoid politics, Meghan has openly spoken up on the #MeToo and Time's Up movements and Prince Harry's feminism, according to Nowak, as well as expressing opinions on abortion.
And the couple has informally engaged with fans.
Royals tend to stick to formal greetings for security and position reasons, but both Meghan and Harry have hugged fans. According to Elyse Dupre of E! News, Harry hugged a fan during his Australian royal tour last year. At an event for International Women's Day, Meghan hugged a 10-year-old fan who wants to be an actress.
On the same trip, she also signed a 10-year-old girl's autograph book with a heart and smiley face — royals aren't allowed to give autographs so their signatures don't get forged, Lakritz said.
In preparation for their first child, Meghan had a lavish baby shower.
According to a Vanity Fair estimate, Meghan's Manhattan baby shower cost $200,000. Serena Williams, a friend of Meghan's, reportedly paid for the party, which included a flower-arranging lesson and dessert tasting with a Michelin-star chef.
Kate didn't have a baby shower, as far as anyone knows, reported Lakritz. Meghan was reportedly told she didn't follow royal tradition, and the Queen's former spokesman told US Weekly baby showers are "an American thing" and that Meghan's "was a bit over the top."
The couple isn't releasing official merchandise to celebrate the birth of the royal baby.
The Royal Collection Trust confirmed to INSIDER that no official merchandise will be released to celebrate the birth of the royal baby, which William and Kate did for all three of their children. Richard Fitzwilliams, a royal commentator, told INSIDER that merchandise is likely considered too "commercial" for Meghan and Harry.
They're opting out of the Lindo wing photo op.
Meghan and Harry skipped the famous Lindo Wing photo op — posing outside the exclusive maternity ward at St. Mary's Hospital a few hours after giving birth — that Princess Diana and Prince Charles began after the birth of Prince William, who continued the tradition with Kate Middleton.
Instead, they hosted a photo op with their new son at Windsor Castle two days following the birth, which is said to have taken place at home. Fitzwilliams told INSIDER the decision could be linked to "Harry's fiercely protective instincts."