The Duke and Duchess of Cambridge have a new niece! Prince William and Kate Middleton celebrated the arrival of Meghan Markle and Prince Harry’s baby girl, Lilibet “Lili” Diana Mountbatten-Windsor, on Sunday with a sweet post on Instagram. The Cambridges shared a previously seen photo, taken by Misan Harriman, that showed a then-pregnant Meghan cradling her son Archie Harrison while Harry sweetly hugged his wife.

“We are all delighted by the happy news of the arrival of baby Lili,” the image was captioned. “Congratulations to Harry, Meghan and Archie.”

William and Kate welcomed another niece earlier this year. The Duchess of Cambridge’s younger sister Pippa Middleton gave birth to her second child, Grace Elizabeth Jane Matthews, on March 15.

The Duke and Duchess of Sussex revealed on Sunday that their second child, Lili, was born on June 4. Meghan gave birth Friday at the Santa Barbara Cottage Hospital in Santa Barbara, CA. The baby girl’s name is a tribute to her late paternal grandmother Princess Diana and great-grandmother Queen Elizabeth. “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 press release on the Sussexes’ Archewell website states.

Following the announcement of the birth of the Queen’s 11th great-grandchild, Buckingham Palace released a statement saying (via HELLO!), “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.”

Her Majesty’s social media accounts also shared a photo of the Duke and Duchess of Sussex from their wedding day writing, “Congratulations to The Duke and Duchess of Sussex on the birth of Lilibet Diana! The Queen, The Prince of Wales and The Duchess of Cornwall and The Duke and Duchess of Cambridge are delighted with the news.”