Lucy Stafford attended Queen Elizabeth's garden party at Buckingham Palace on Tuesday and snapped a candid pic of the royal couple that she posted on Instagram

By Stephanie Petit
May 22, 2019 12:55 PM

One of the most romantic photos of Kate Middleton and Prince William wasn’t taken by a professional photographer — or even posed!

Lucy Stafford attended Queen Elizabeth‘s garden party at Buckingham Palace on Tuesday and snapped a candid pic of the royal couple that she posted on Instagram. William, 36, appears eager to show his wife something, pointing and taking her by the arm. Kate, 37, flashes a smile in her light pink Alexander McQueen ensemble, with her arm outstretched as if in the middle of a dance.

With their polished outfits — especially Prince William‘s top hat! — and excited expressions, the adorable shot could be straight out of a musical or movie (there are some strong Mary Poppins vibes!).

Kate Middleton and Prince William
Courtesy Lucy Stafford

Stafford, 19, was invited to the garden party for creating Hospital Love Bundles, an organization that cheers up young people during hospital stays through care packages. She has Ehlers Danlos Syndrome (EDS), which causes her digestive tract to fail, and came up with the idea through her own experience in the hospital.

On top of enjoying “the most delicious afternoon tea in the beautiful gardens,” Stafford met the Queen, Kate and William during Tuesday’s event.

“The royal family, including the Queen, circulated the party and were so incredibly kind,” she tells PEOPLE, adding that she was even treated to a funny story by the 93-year-old monarch. “The Queen reminisced about when she was almost hit by a cricket ball at a match in 1994. Luckily her bodyguard caught it, or she said she would have been dead!”

Queen Elizabeth

Stafford also chatted with Kate about her children — Prince George, 5, Princess Charlotte, 4, and Prince Louis — visiting the “Back to the Nature” garden she helped design for the Chelsea Flower Show in London.

“Such a lovely day, and I feel so lucky to have been able to attend,” she tells PEOPLE.

Kate Middleton and Prince William
Dominic Lipinski - WPA Pool/Getty
Kate Middleton and Prince William
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The skies were clear as Queen Elizabeth hosted the second garden party of the year at Buckingham Palace. The monarch even wore sunglasses (a rare look for her!) and carried an umbrella in case she was in need of some quick shade.

The Queen was delighted by the good spring weather, telling Victoria English, a 50-year-old teacher from Wales, “Well, you do rather hope the sun shines as when you invite 8,000 people to have tea on your lawn. It can be a bit of a worry.”