The Queen had a close relationship with all of her grandchildren and great-grandchildren, but a break of royal protocol for Meghan Markle proved Prince Harry had a "special place" in her heart, an expert has claimed.
Shortly after the couple's engagement in 2017, the royals all travelled to Sandringham for their annual Christmas break.
However Meghan, who was living in the UK at the time, shouldn't have been on the guestlist as royal partners aren't normally allowed to attend until they have officially married into the family.
But the Queen made decision to break this rule and extend the invitation to her grandson's girlfriend, giving her first insight into royal life ahead of her wedding.
Writing for the Mail on Sunday, Penny Junor claims this decision proved the Queen's special relationship with Harry.
She says: "But as is often true in families, her relationship with her grandchildren was very much easier than it was with her children. It was certainly true of her relationship with her first-born, Prince Charles, and his sons, William and Harry.
"She had the most enchanting relationship with all of her grandchildren and indeed her great-grandchildren, and was hugely fond of them all, but there was a special place in her heart for William and Harry.
"When Harry became engaged to Meghan Markle in 2017, she abandoned the old protocol about only married being allowed, and invited Meghan to spend Christmas with them all at Sandringham."
During her controversial interview with Oprah Winfry, Meghan recalled her first meeting with the Queen, which took place at Royal Lodge in Windsor after a church service.
She said: "Harry and I are in the car, and he says, 'Okay, well, my grandmother says you're going to meet her,'" she recalled. "I loved my grandmother, I used to take care of my grandma, this is great."
Harry then asked her if she knew how to curtsy, which she said was the first moment "the penny dropped" that royal life "wasn't going to be easy".
Meghan practised how to curtsey outside the house before heading inside. She told Oprah: "And then, we just sat there and we chatted, and it was lovely and easy."
She later added: "The queen has always been wonderful to me."
Meghan carried out one joint engagement with the Queen during her short time as a working royal, travelling to Chester with the Monarch for a day of engagements.
They were seen chatting and joking as they attended the events, with the Queen even offering her guidance when she got confused about protocol as they got into a car.
Meghan joined Harry and the Prince and Princess of Wales for a surprise walkabout at Windsor to view tributes to the Queen after a last minute invitation.
Despite their well-documented troubled relationship, William and Harry reunited to greet well-wishers for about 45 minutes.
It has been two years since William, Kate, Harry and Meghan were together side-by-side in public, the last time being at the 2020 Commonwealth Day church service.
A senior source said: "The Prince of Wales thought it was an important show of unity at an incredibly difficult time for the family."
During the appearance, the four royals shook outstretched hands, joked with crowds and received flowers for the late Queen.
Prince Harry also played with a dog while Meghan hugged an emotional teenager.
