Princess Eugenie took to Instagram to send the message to her beloved sister and brother-in-law congratulating the couple on the arrival of their daughter. Princess Beatrice and Edoardo Mapelli Mozzi welcomed their first child together to the world on Saturday evening.

       Eugenie's gushing Instagram post to the new parents read: “To my dearest Beabea and Edo.

       "Congratulations on your new angel.

       “I can't wait to meet her and I'm so proud of you.

       “We're going to have so much fun watching our children grow up.

       “Love Euge.

       The Princess also included a message welcoming her new niece to the world.

       In her message to her new niece, Princess Eugenie adorably urged her to call her “Auntie Euge”.

       The message read: “To my new niece.

       “I love you already and think you're just awesome from the photos…

       “We're going to have so much fun together.

       “Love your Auntie Euge.

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       Princess Beatrice’s daughter is her first child but she is already a stepmother to Edoardo's stepson Christopher Woolf.

       The baby has also become the Queen’s 12th great-grandchild, as well as being the second grandchild for Prince Andrew and Sarah Ferguson.

       Princess Beatrice gave birth to her baby girl at the Chelsea and Westminster Hospital in London.

       Their child arrived at 11.42pm, weighing six pounds and two ounces.

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       The statement from Buckingham Palace read: “Her Royal Highness Princess Beatrice and Mr Edoardo Mapelli Mozzi are delighted to announce the safe arrival of their daughter on Saturday 18th September 2021, at 23.42pm, at the Chelsea and Westminster Hospital, London.

       "The baby weighs 6 pounds and 2 ounces.

       “The new baby’s grandparents and great-grandparents have all been informed and are delighted with the news.

       “The family would like to thank all the staff at the hospital for their wonderful care.

       “Her Royal Highness and her child are both doing well, and the couple are looking forward to introducing their daughter to her big brother Christopher Woolf."

       Princess Beatrice also took to Twitter to share the news as she said she was “delighted to share the news of the safe arrival of our daughter on Saturday 18th September 2021, at 23.42pm at the Chelsea and Westminster Hospital, London."