Taking a brief break from her royal duties this weekend, Kate Middleton was still on mom duty while preparing for Queen Elizabeth's Platinum Jubilee ongoing celebrations — and in inimitable Kate style, she pulled out the perfect outfit for even the most laid-back occasion.

On Sunday, the Duchess of Cambridge shared a photo montage of herself and her three children — Prince George, 8, Princess Charlotte, 7, and 4-year-old Prince Louis — in the kitchen at home, baking cupcakes together for the festivities. In the clip shared to Kate and Prince William's grid, Kate swapped out her coat dresses and heels for a relaxed, albeit rather chic, off-duty uniform that consisted of high-waisted mom jeans and an essential summer classic: a gingham-patterned top. Her pink shirt was tucked into the light-wash denim and featured a ruffled Peter Pan collar, as well as puff sleeves. She accessorized with her sapphire and diamond engagement ring, a matching pendant necklace, and a bouncy blowout.

"Baking cakes for the local community in Cardiff to enjoy at a Platinum Jubilee street party taking place today! 🎉," the caption read. "We hope you like them! 🧁" George, Charlotte, and Louis were also dressed casually in polo shirts and shorts, as they prepped, poured, and mixed the cupcake batter. Kate, meanwhile, was in charge of adding sprinkles to the iced vanilla treats.

The Cambridges seemingly baked the cupcakes ahead of their visit to Cardiff Castle in Wales on Saturday, where George and Charlotte joined their parents and mingled with the performers and crew who were preparing for the Celebration Concert. During the appearance, the young royals adorably conducted an orchestra to the tune of "We Don't Talk About Bruno" from Disney's Encanto, after shaking hands and chatting with well-wishers on the castle grounds.