Over the years, Queen Elizabeth II has welcomed many a royal baby into the Royal Family.... And in 2021 alone, four royal babies were born, bringing the total number of the Queen's great-grandchildren to 12.... Read on to find out more about the Royal Family's youngest members. Sienna Elizabeth Mapelli Mozzi was born on September 18, 2021. Sienna is Princess Beatrice's first child with her husband Edoardo Mapelli Mozzi. Place in line of succession to the throne: 11thLilibet Diana Mountbatten-W