The Prince of Wales and Duchess of Cornwall arrive at Buckingham PalaceCredit:Mark Stewart Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. The Duchess of Gloucester drives herself to the Christmas lunch Credit:Jonathan Brady /PA The Duke and Duchess of Cambridge arrive at Buckingham PalaceCredit:Jonathan Brady /PA Prince and Princess Michael of Kent’s daughter Gabriella of Windsor in the back of the couple’s carCredit:Philip Toscano /PA Among the other Royals to attend the event were Prince and Princess Michael of Kent and their daughter Lady Gabriella Windsor. Prince George looks out the window of a car driven by his father, the Duke of CambridgeCredit:Tim Rooke/REX/Shutterstock Prince Harry introduced Meghan Markle to the nation in Nottingham earlier this monthCredit:Joe Giddens /PA Sisters Princess Beatrice and Princess Eugenie, the Duke of York’s children, were also spotted arriving for the lunch by car. Meghan Markle has joined Prince Harry at Buckingham Palace to attend the Queen’s Christmas lunch, as she is further welcomed into the Royal family.The US actress was photographed in the passenger seat of a Land Rover Discovery driven by her fiance as they arrived for the event on Wednesday afternoon.The couple looked relaxed as they passed waiting photographers. The prince, 33, was smartly dressed in a suit, shirt and tie and the 36-year-old former Suits star wore a patterned outfit.The Queen traditionally hosts a festive lunch for her family before leaving for her private Sandringham estate, where she spends her winter break.It has already been confirmed that Ms Markle will be part of the Royal party at Sandringham for Christmas and is expected to greet crowds ahead of the morning church service.Her appearance at the Buckingham Palace lunch is another indication of how quickly she has been accepted into the monarchy ahead of the wedding. Tradition reportedly dictates that the lunch is attended by only relatives and spouses. It is believed to be the first time that Ms Markle will have met many of Prince Harry’s extended family members.The Duke of Cambridge drove his family into Buckingham Palace, with the Duchess of Cambridge in the passenger seat of the Range Rover.Their children, Prince George and Princess Charlotte, sat in the rear seats either side of their Spanish nanny, Maria Teresa Turrion Borrallo. Princess Charlotte gazes at photographers through the windscreen as the family arrive at Buckingham PalaceCredit:Andrew Parsons / i-Images The Prince of Wales and the Duchess of Cornwall smiled at passers-by and tourists who were likely delighted at the unexpected chance to see so many members of the Royal family. The Duchess of Gloucester and Princess Alexandra were among the other attendees. The Royal family are paying for the wedding, including the church service, the music, the flowers and the reception.But the security costs for the high-profile event are falling to the taxpayer. Princess Beatrice smiles as she attends the Christmas lunchCredit:Tim Rooke/REX/Shutterstock Her sister, Princess Eugenie, was also pictured arriving for the family get-togetherCredit:Jonathan Brady /PA After the couple’s engagement was announced last month, Ms Markle, the American actress, is set to appear at church with the Windsors at Sandringham on Christmas Day. Prince Harry and Ms Markle will be married on May 19 at Windsor Castle’s St George’s Chapel – an event which will be one of the royal highlights of 2018.They got engaged on November 27 and a few days later a proud prince introduced his bride-to-be to the nation during a series of official events in Nottingham. Princess Alexandra (right) is in jovial mood as she arrives at Buckingham PalaceCredit:Jonathan Brady /PA Prince and Princess Michael of Kent arrive at the gates of Buckingham PalaceCredit:Jonathan Brady /PA Meghan Markle was driven into Buckingham Palace by Prince Harry in a Land Rover DiscoveryCredit:Tim Rooke/REX/Shutterstock Palace aides have already said that the prince and Ms Markle’s wedding will “reflect their characters and personalities” and be a moment of “fun and joy”.They will tie the knot in the historic surrounds of the Castle’s 15th century St George’s Chapel.Ms Markle, who is to become a British citizen, is being both baptised and confirmed ahead of the religious ceremony. The Queen will be there, as will the rest of the Royal family, along with Ms Markle’s parents Thomas Markle and Doria Ragland.Prince George and Princess Charlotte look set take on the roles of pageboy and bridesmaid.Full interview: Harry and Meghan reveal engagement joy Harry proposed to Suits star Ms Markle during a cosy night in over a roast chicken dinner after a 16-month whirlwind romance.In their engagement interview he told of how “the stars were aligned” when he fell for his future wife, whom he met on a blind date. Dozens of members of the extended Royal family – most of whom do not get an invitation to Sandringham – gather each year for the family get-together.