Instead of the royal family, members from the Spencer family were invited to attend the unveiling.
William took on the role of elder brother and appeared "thoughtful and in control" while Harry looked "more nervous."
It comes weeks after Kate told reporters that she hasn't yet had a video call with her newborn niece Lili.
The new development comes just before they are due to jointly unveil their mother Princess Diana's statue at Kensington Palace.
Meanwhile, a royal expert claimed that Harry is willing to admit his mistakes, but Meghan and William are unwilling to budge.
The rare appearance comes soon after a report that George was told about his future as the King of England almost a year ago.
Royal expert says William's close relationship with his mother-in-law is one of the key differences between him and his younger brother Harry.
The Diana Award honors young persons aged 9-25 who work to improve the lives of others with their social action or humanitarian work.
Royal biographer Andrew Morton said The Princess of Wales would have been working with Prince Charles to reconcile William and Harry.
A network of "devoted friends and a few family members are working seriously" to broker peace between the warring brothers.
Mutual friends of the brothers say neither of them are willing to offer each other an "olive branch" ahead of their reunion.
The Duke and the Duchess of Cambridge held off the knowledge from their eldest son as they wanted him to have a "normal family upbringing."
The honey was made at Anmer Hall, the country home in Norfolk Kate shares with her husband Prince William and their three children.
Royal historian says "it was no accident" that other members of the royal family were also not publicly seen speaking with Harry on the day of the funeral."
The Duke of Sussex doesn't want to leave the coverage of the statue unveiling to the official "Royal Rota" of journalists.
William believed that Meghan had an "agenda" and his wife Kate Middleton had also been "wary" of the former actress "from the start."
Harry won 22 percent of the votes compared to his elder brother William who got 10 percent.
A report says it was hard for Harry to attend his grandfather's funeral alone and Meghan doesn't want that to happen again.
The moniker was revealed when Kate reunited with Prince Charles on Friday evening for the G7 summit.
The 39-year-old spoke about her niece while visiting a school in Cornwall with United States first lady Jill Biden.
Prince Edward said his "self-effacing" father "wouldn't have wanted the fuss and the bother" if he lived to see this day.
The Duke of Sussex is due to attend the unveiling of his mother Princess Diana's statue at Kensington Palace on July 1.