Queen Camilla and Catherine, Princess of Wales
Queen Camilla and Catherine, Princess of Wales, at The National Service of Remembrance on Sunday, November 12, 2023. The Prince and Princess of Wales/Twitter

Kate Middleton had royal watchers expressing concern after photos from The National Service of Remembrance on Sunday, November 12, showed her looking "old" standing next to Queen Camilla.

The royal women joined other royal family members, politicians, and veterans as they paid tribute to those who died or suffered during wartime from a balcony above The Cenotaph war memorial in London. The 41-year-old mum-of-three cut a solemn figure in an all-black Alexander McQueen military-inspired coat which she adorned with three red poppies.

The Princess of Wales also wore a silver brooch awarded to her when she became Commodore-in-Chief of the Fleet Air Arm earlier this year. She had her hair in a chic updo and paired it with a large Philip Treacy hat decorated with a velvet bow.

The royal maintained a solemn look during the service but at one point broke into a smile during a conversation with Queen Camilla. She also appeared to fight back tears as she watched the activities down below, where Prince William, King Charles III, Prince Edward, and Princess Anne laid wreaths at the memorial.

Photos have since been shared online from Remembrance Sunday and royal watchers took to X, formerly Twitter, to comment on Kate Middleton's appearance. There were those who complimented her and Queen Camilla on their elegant looks.

One praised: "The royal ladies always look elegant and sophisticated" and a second chimed in: "Beautiful Princess Catherine, the one and only!"

A third wrote: "Lovely pic of two strong classy woman who truly belong on that balcony." One more added: "Princess Catherine is wearing the late Queen's poppy that's an honour and she looks queenly."

Meanwhile, there were those who said Kate Middleton has aged and that the strain is showing on her face. One even suggested that she should leave the institution because she is "aging terribly".

"I don't think she's happy. Girl your happiness is more important than this- Diana left and made a greater impact on the world. You are more than they let you think you are. You can make it. Believe in yourself!" one tweeted.

Another shared a comparison photo from a previous appearance at Remembrance Sunday to show how she has aged over the years. One even claimed that the Princes of Wales "looks as old as (Queen) Camilla".

Another commented: "Katie looks so terribly sad...worn out from all that hard work she does...Her house staff need to give her more breaks."

A second wrote: "Look at those sad eyes and mouth. a very unhappy woman" and a third claimed: "Hate really ages one".

"Look at the state of her," one more commented and another chimed in: "She is looking worse for wear."

"She's aging fast. Her and William look like 50 year olds," another claimed.

The National Service of Remembrance started with a two minute silence across the U.K. at 11:00 a.m. Then King Charles III led the country at the Whitehall memorial in commemorating the end of the First World War and other conflicts involving the Commonwealth and British forces.

His Majesty laid a wreath similar to the one produced for King George VI which featured 41 open style poppy petals crafted from bonded fabric mounted on an arrangement of black leaves. Major Ollie Plunket laid a wreath for Queen Camilla which resembled the one produced for the Queen Mother.

Among the senior politicians who laid wreaths included U.K.'s Prime Minister Rishi Sunak, James Cleverly, Sir Keir Starmer, Suella Braverman and Sir Ed Davey. Former prime ministers Liz Truss, Boris Johnson, David Cameron, Gordon Brown, Theresa May, Sir Tony Blair and Sir John Major were also in attendance.

A day before Remembrance Sunday, King Charles III, Queen Camilla, Prince William and Kate Middleton were at Royal Albert Hall for the Royal British Legion Festival of Remembrance.