Kate Middleton might be joining her husband Prince William at the unveiling of his mother Princess Diana's statue in the Sunken Garden at Kensington Palace, instead of his brother Prince Harry.

It is being speculated that Prince Harry, who welcomed a baby girl with his wife Meghan Markle on Friday, June 4, won't be able to travel from California to the UK for the unveiling next month. According to royal expert Russell Myers, the Duchess of Cambridge may "step in" for her brother-in-law in this case.

In a conversation with Daily Mirror's "Pod Save The Queen" which was aired before the Sussexes announced the arrival of their daughter on Sunday, Myers said that the baby could derail Harry's plans to attend the event as she will be less than a month old at the time.

"Maybe Kate will step in to not have William do it on his own," Myers said.

The event is being held on July 1, which would have been the 60th birthday of the late Princess of Wales. Prince William and Prince Harry had commissioned her statue in 2017 to mark the twentieth anniversary of her death and to recognise her positive impact in the UK and around the world. It is their only remaining joint project since Harry quit as a senior royal in March last year.

Even if the Duke of Sussex manages to attend the unveiling, his reunion with William is expected to be a tense one, given his numerous interviews about the royal family. The brothers had met during the funeral of their grandfather Prince Philip in April, but Harry has made a whole new set of allegations against the royal family since then.

"Will there be an appetite for him to keep on criticising his family in that way? He's potentially going to be standing shoulder-to-shoulder with his brother when they unveil the Princess Diana statue," Myers said, adding, "That could make it very, very uncomfortable."

However, Harry and Meghan have seemingly extended an olive branch to the royal family by naming their daughter Lilibet Diana Mountbatten-Windsor, the first name a moniker for Queen Elizabeth II.

Kate Middleton
Prince Harry and Kate Middleton arrive for the official opening of The Global Academy in support of Heads Together at The Global Academy in Hayes, London Chris Jackson/Getty Images