It has not been confirmed who will join Her Majesty on the iconic viewpoint, but royal watchers are hoping Kate will make a second appearance.
Kate is now in the middle of maternity leave for Prince Louis and hasn't yet returned to full-time royal duties.
The outlet reported that Kate felt the celebration was important to be at if she was feeling up to it. Kate Middleton went with an icy blue dress by her go-to designer, Alexander McQueen, and a hat by Sean Barrett.
It was another huge moment for Meghan, who has been adapting to life as a member of the royal family since she married Harry at Windsor Castle on May 19. This marks the first time the Duchess of Sussex has worn the French label.
The Duchess has made subtle changes to her look since marrying Harry, opting for clutch bags, and has ditched the messy bun in favour for a more sleek style. Yesterday, July 9, in London was the christening of their Prince William third child of Prince Louis.
Kate Middleton wore a pastel blue Alexander McQueen jacket to the RAF 100th anniversary celebration on Tuesday. The Queen is rarely seen outdoors without a hat, usually in a colour that matches her outfit. She also wore the diamond and ruby RAF Dacre brooch, which was given to her in 2015.
Just one day after attending the christening of Prince Louis, the royal family was out and about again to celebrate the 100th birthday of the Royal Air Force.
Royal experts have continued to draw comparisons between the two women, ever since Kate and Prince William announced their engagement in 2010.
According to Harper's Bazaar, Kate wore a white dress with puff sleeves and a midi-length hemline.