Duchess of Cambridge, Kate Middleton, was reportedly a little worried that her children might misbehave at her sister Pippa's wedding, according to news reports, but it turns out that the royal children were on their best behavior — and they nearly stole the show.

"She said that they were all really looking forward to her sister's wedding at the weekend, but she was a bit worried about how her children might behave," Kate reportedly said during a recent garden party at Buckingham Palace, according to media outlets last week.

“She said she was hopeful that they would be good, but you never know at that age,” the source said.

Prince George, 3, and Princess Charlotte, 2, joined a group of other young children in the wedding party as page boy and flower girl, wearing matching outfits for the Saturday wedding at St. Mark's Church in England. At the ceremony, guests noted that the children were "very" well-behaved for the nuptials.

Prince George, second from left, and Princess Charlotte on the far right, were part of their aunt Pippa Middleton’s wedding party at her marriage to financier James Matthews on May 20.

Credit: Justin Tallis

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Credit: Justin Tallis

“It was amazing,” one guest noted.

Middleton married financier and hedge fund manager Matthew James, whom she had been dating on-and-off since 2012. The couple got engaged last July.

ENGLEFIELD GREEN, ENGLAND - MAY 20: Pippa Middleton and her new husband James Matthews are seen with Catherine, Duchess of Cambridge and her children Prince George of Cambridge and Princess Charlotte of Cambridge leave church following their wedding ceremony at St Mark's Church as the bridesmaids and pageboys walk ahead on May 20, 2017 in Englefield Green, England.  (Photo by Justin Tallis - WPA Pool/Getty Images)

Credit: WPA Pool

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Credit: WPA Pool