Photo: Daniel Leal - WPA Pool/Getty Images

Prince George of Wales, Prince Louis of Wales (R) and Princess Charlotte of Wales pose for a group picture with volunteers who are taking part in the Big Help Out, during a visit to the 3rd Upton Scouts Hut in Slough

Princess Charlotteis a typical big sister to little brotherPrince Louis!

Princess Charlotte, 8, and Prince Louis, 5, joinedPrince William,Kate Middleton, andPrince GeorgeatThe Big Help Outon Monday, a bank holiday in the U.K. that encourages volunteer work in honor ofKing Charles' coronation. The Prince and Princess of Wales and their three childrenvolunteeredat the 3rd Upton Scout Group in Slough to pitch in on various projects, and a fellow helper exclusively tells PEOPLE Charlotte didn’t shy away from keeping her brother in line!

Anne Edwards is an adult Scout helper and worked with Charlotte and Louis to paint cinder blocks to support wooden planters, where she caught the adorable exchange between the siblings.

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Princess Charlotte of Wales (R) and her brother Britain’s Prince Louis of Wales (R) eat marshmallow biscuits as they take part in the Big Help Out, during a visit to the 3rd Upton Scouts Hut

Prince Williamand Princess Kate’s only daughter is “a bit older and is more sensible” and kept an eye on her younger sibling at hisfirst royal engagement.

“She was advising him, obviously! ‘Don’t do that, Louis!’ — things like that,” Edwards says, adding that seeing the Wales children so enthusiastic about the effort was lovely.

Princess Charlotte of Wales stains some wood while taking part in the Big Help Out, during a visit to the 3rd Upton Scouts Hut in Slough

“They were very relaxed and joining in, like normal kids. That was what was really nice about it,” the volunteer says.

Princess CharlotteandPrince Louis’tight bondwas on display during King Charles andQueen Camilla’s crowning ceremony at Westminster Abbey on Saturday, where they sweetly held hands on the way in and out of the event and sat together during the service. The Prince and Princess of Wales' two youngest children watched with pride as big brotherPrince George, 9, stepped up to serve as aPage of Honor for King Charles, carrying a corner of his robe during processions.

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Prince George and Princess Charlotte arrive for the Coronation of King Charles III and Queen Camilla on May 6, 2023

During asurprise appearanceat a Big Lunch along the Long Walk outside Windsor Castle on Sunday,Prince Williamjoked that Charlotte was tired after keeping an eye on Louis the day before.

According toHello!, when a little girl asked the Prince of Wales, 40, where Charlotte was, he replied, “She’s very tired after yesterday. She’s having a quiet day at home. It was making sure her little brother behaved himself.”

Prince William and Kate Middleton

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Though Charlotte stayed in for the Long Walk, she did join her parents and George for the Coronation Concert at Windsor Castle on Sunday night. Thecameras caughtthe brother and sister standing and dancing from their spots in the royal box, animatedly waving their Union Jack flags as Lionel Richie performed “All Night Long.”

Little Louis wasn’t in attendance — as the party was likely past his bedtime!

source: people.com