Prince Harry's daughter's name has something in common with her cousin Charlotte

The Duke and Duchess of Sussex's daughter already has one very special thing in common with her cousin Princess Charlotte.

On Sunday, the Prince Harry and Meghan announced the birth of their second child, a daughter named Lilibet “Lili” Diana Mountbatten-Windsor, and the newborn's name is a tribute to her late grandmother, Princess Diana, and also Queen Elizabeth II.

"Lili is named after her great-grandmother, Her Majesty The Queen, whose family nickname is Lilibet," the couple explained in a statement. "Her middle name, Diana, was chosen to honor her beloved late grandmother, The Princess of Wales."

Lili's name holds special meaning, much like her cousin, Princess Charlotte. The 6-year-old's full name is Charlotte Elizabeth Diana, and both of her middle names also pay tribute to the queen and Diana.

Related: The Duke and Duchess of Sussex paid tribute to Queen Elizabeth II and the late Princess Diana with their daughter's name.

It might be a while until Lili, who was born in Santa Barbara, California, meets her cousin Charlotte, but the royal family has already begun sending their well wishes to the duke and duchess.

Over the weekend, Buckingham Palace shared the following statement with TODAY: “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."

The Duke and Duchess of Cambridge also expressed their excitement over the news on Instagram, writing, "We are all delighted by the happy news of the arrival of baby Lili. Congratulations to Harry, Meghan and Archie."

Related: Prince William and the Duchess of Cambridge have named their new daughter Charlotte, the recent favorite with the betting public.

So, where does the name Lilibet come from?

It was Elizabeth's nickname as a child since she had trouble pronouncing her full name. She has used it throughout her life and even signed the name on a letter that was placed on her late husband Prince Philip's coffin, royal experts told TODAY.

Related video: