Despite being close over the years, the two are believed to have hit rocky ground since Harry began dating Meghan Markle.
Leaving a charity concert at St. Luke's Church in London, covert pictures of the Duchess were snapped and shared by Daily Mail's royal correspondent Emily Andrews on Twitter. According to one source, Kate has been "advising Meghan on what lies ahead".
But Harry is believed to have stood up for Meghan "very forcibly" - a sign that he "really loves her".
The Duchess of Sussex has always been very health conscious, so it should come as no surprise that a day in the life of Meghan Markle starts with a green juice.
This mirrors a Vanity Fair report which claimed that the two brothers had a fall-out previous year when Harry felt that his older brother was not trying hard enough to welcome Meghan into the family.More news: The Fortnite Season 7 Official Trailer is here
And if that isn't reason enough for the Royal brides to sit down nicely next to each other at Christmas dinner and give each other a heartfelt hug to the shock of all, then I'll tell them something.
Since her marriage to Prince Harry, Markle has been seen out and about several times in flowy business chic trousers.
Prince Harry's reaction was stormy, the courtier said.
Harry added that they 'come so thick and fast'.More news: Fandango Offering 50% Off Golden Globes-Nominated Movies and TV Shows
Members of the royal family gathered at Buckingham Palace on Tuesday evening for a reception for members of the Diplomatic Corps.
The senior royals are said to be wanting to nip rumours of tension in the bud and are calling on them to display a united front.
Prince William is reported to have told his father what was happening and Prince Charles chose to intervene.
It may look familiar to fans of the royals because Meghan Markle is known for being a fan of smart suits, including breezy dress trousers.
Kensington Palace was not consulted on the contents of the musical.More news: Nation says goodbye to Bush: 'To us, he was close to perfect'
However in a glimmer of hope, the two brother are said to have sat down last week and worked out their diaries for next year.