Kate "often jokes that he's the only one of her kids who actually looks like her," a friend told PEOPLE


Kate Middleton has a mini-me in son Prince Louis!

In honor of Mother's Day in the U.K. on Sunday, Kate and Prince William shared a rare photo from the Duchess of Cambridge's childhood on their social media pages. In addition to paying tribute to Kate's mom, Carole Middleton, the photo showed a young Kate — who could easily be mistaken for her youngest child.

While both Prince George, 7, and Princess Charlotte, 5, have some similar traits to their mother, 2-year-old Prince Louis shares Kate's brunette hair, brown eyes and sweet smile — and the resemblance is uncanny.

Kate, 39, has even acknowledged Prince Louis is taking after her looks.

Catherine, Duchess of Cambridge; Prince Louis
Credit: Kensington Palace Instagram; Aaron Chown - WPA Pool/Getty Images

"Everyone always comments on how Louis is the spitting image of Kate," a friend previously told PEOPLE. "She loves it and thinks it's very sweet — she often jokes that he's the only one of her kids who actually looks like her!"

Cambridges attend pantomime
Prince Louis and Kate Middleton
| Credit: AARON CHOWN/POOL/AFP via Getty

The Cambridge kids made sure it was a special Mothering Sunday for Kate this year by baking her a cake topped with sprinkles and pipe cleaners crafted into heart shapes.

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In addition, Prince George, Princess Charlotte and Prince Louis made cards for their late grandmother, Princess Diana.

In addition to the colorful artwork, Kate and Prince William's two eldest children shared sweet messages to "Granny Diana."

"Dear Granny Diana, Happy Happy mothers day," wrote George. "I love you very much and think of you always. Sending you lots of love." 

"I am thinking of you on mothers day. I love you very much," said Charlotte in her own card. "Papa is missing you. Lots of love." 

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After spending much of the year at the country home during lockdown, the Cambridge family recently returned to London, where Prince George and Princess Charlotte attend school.