Buckingham Palace announced on Friday that the Queen’s 12th great-grandchild has been named Sienna Elizabeth Mapelli Mozzi. Princess Beatrice’s husband Edoardo Mapelli Mozzi shared a photo of the footprints of his baby girl, who was born on Sept. 18. “Sienna Elizabeth Mapelli Mozzi. Our life together has just begun, and I can’t wait to see all the amazing things that await us,” he wrote on Instagram. “These are the days I never want to forget. This week, a friend said to me the sweetest saying….that with every child you grow a whole new heart.”

Beatrice, 33, is the oldest daughter of Prince Andrew and Sarah Ferguson. The name Elizabeth is a tribute to Beatrice’s grandmother, the Queen.