Eugenie celebrated the arrival of the latest royal family member Lilibet "Lili" Diana Mountbatten-Windsor, named for both Queen Elizabeth and Princess Diana

Princess Eugenie is celebrating the newest addition to the royal family all the way across the pond.

The royal congratulated cousin Prince Harry and Meghan Markle on their newborn daughter on Sunday. "Congratulations dear cousins.. we couldn't be happier for you all," Eugenie shared on her Instagram Story under a black-and-white photo of the couple.

The Duke and Duchess of Sussex welcomed their second child, a baby girl, at 11:40 a.m. on Friday. "On June 4th, we were blessed with the arrival of our daughter, Lili," the proud parents confirmed on their website Archewell.

Princess Eugenie's Instagram
Princess Eugenie's Instagram

"She is more than we could have ever imagined, and we remain grateful for the love and prayers we've felt from across the globe," Harry and Meghan added. "Thank you for your continued kindness and support during this very special time for our family."

The Duke and Duchess, who also share 2-year-old son Archie Harrison, named their daughter Lilibet "Lili" Diana Mountbatten-Windsor. "Lili is named after her great-grandmother, Her Majesty The Queen, whose family nickname is Lilibet. Her middle name, Diana, was chosen to honor her beloved late grandmother, The Princess of Wales," a statement from the couple explained.

Prince William and Kate Middleton also shared sweet sentiments on their Instagram account, writing, "We are all delighted by the happy news of the arrival of baby Lili.Congratulations to Harry, Meghan and Archie."

"The Queen, The Prince of Wales, and The Duchess of Cornwall, and The Duke and Duchess of Cambridge have been informed and are delighted with the news of the birth of a daughter for The Duke and Duchess of Sussex," a spokesperson for Buckingham Palace also confirmed.

Listen below to our daily podcast PEOPLE Every Day for more on Prince Harry and Meghan Markle's new daughter, Lilibet Diana.

Baby Lili comes just four months after Princess Eugenie welcomed her own bundle of joy in February, a son named August Philip Hawke Brooksbank, whom she shares with husband Jack Brooksbank.

Harry and Meghan even lent Eugenie and Jack the use of Frogmore Cottage as they begin their new lives as parents. In fact, in the early days of the Sussexes' relationship, Eugenie and Jack went on double dates with Harry and Meghan, which shows just how close the cousins are.