Watch Kate Middleton's Reaction After Fan Says She'll Be 'Brilliant Princess Of Wales'

Kate Middleton received a sweet compliment from a fan during a royal outing earlier this month.

On June 4, the Duchess of Cambridge and her husband Prince William visited Cardiff Castle in Wales alongside their children, Prince George, 8, and Princess Charlotte, 7, in honor of Queen Elizabeth's Platinum Jubilee celebrations.

The couple took the time to chat with well-wishers outside the castle during the outing.

In a video shared on Twitter by user @Hellen3030, one woman shook the future queen consort's hand and told her: "You're going to be a brilliant Princess of Wales."

Middleton appeared very touched, smiling and saying in response, "Oh, that's very kind."

The duchess then gestured toward Prince William, adding, "I'm in good hands."

The Twitter user who captured the sweet moment and shared it online told People that the Cambridges "are humble and a lovely family."

"I flew last minute from Miami to attend the Platinum Jubilee and decided to go to Cardiff the day before. I met wonderful people from all over the world wanting to meet them," the royal fan added. "We had no idea they were bringing Prince George and Princess Charlotte until later on. Once we met the Cambridges, we were all mesmerized by them. I missed my train back to London and arrived late to the Platinum Party at the Palace, but it was all worth it!"

Other royal fans and Twitter users reacted to the video, praising Middleton's grace and humility.

"Such a lovely thing to say and so humble. She still relies on him to give her direction. Even after 20 years together," one person commented.

"Thank you for sharing this!! Wonderful! There is so much to admire about her," another added.

"You're so right! She does get it and that is part of her success in her role. From day one, she has known it is all about William and that she would always be the supporting act, never the lead. It takes a really insightful woman to know this, accept it and embrace it," another person wrote.

Middleton could inherit Princess Diana's title of Princess of Wales when Prince William becomes the immediate heir to the throne and takes the title of Prince of Wales after his father Prince Charles becomes king, according to People.

Middleton faces intense pressure as the U.K.'s future queen. Sarah Gristwood, author of "Elizabeth: The Queen and the Crown," told People that those who know the Duchess of Cambridge say "there is a real core of strength, and she did set her mind to the job."

"But at the same time, she'd have to be superhuman not to feel the pressure," Gristwood added.