Kate Middelton politely declined signing autographs at her appearance on Monday at the Chelsea Flower Show.
The Princess of Wales, 41, made a surprise visit at the inaugural Children's Picnic where she shared an unspoken royal rule with a few elementary school-aged kids.
"I can't write my name," Middleton said, according to People magazine, "but I can draw."
The outlet reported that the princess drew a flower for a 7-year-old girl named Ruby, a tree for another young girl and a pond with flowers for another child.
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"My name's Catherine. I'm not allowed to write my signature, it's just one of those rules," Middleton told the children when asked why she could not sign her autograph, the outlet reported.
During her surprise outing to the Royal Entomological Society garden, Middleton shared with the children attending that her youngest son, Prince Louis, is taking up some gardening himself.
"Louis is growing broad beans at school. You put them in a cup, and you can see the roots growing. They get big quickly like sunflowers," Middleton said.
Middleton shared with the school children the importance of spending time outdoors. "It's so good for our bodies and our minds," she said.
The official Instagram account for the Prince and Princess of Wales shared a picture of Middleton during her outing on Monday.
"Picnic season is upon us, and so is @the_rhs #ChelseaFlowerShow!" the caption began. "What a lovely lunchtime spent with the next generation of nature-lovers, exploring the gardens and enjoying the first ever Children’s Picnic here at Chelsea."
Middleton's visit comes after her husband, Prince William, took to Instagram on Sunday to share a video of himself rowing alongside HMS Oardacious, a royal navy team of submariners who focus on mental health.
"Joining the past, present and future crews of HMS Oardacious for a very important conversation about mental health," the Prince and Princess of Wales Instagram caption read.
"For #MentalHealthAwarenessWeek we headed out onto the water, chatting everything from teamwork to food rations and just what it takes to look after your mental health when rowing across the Atlantic," the caption continued.
William put his athletic abilities on display as he rowed alongside members of the royal navy team.
The royal couple have been longtime advocates for mental health awareness and launched the Heads Together initiative in 2016, "which combines a campaign to tackle stigma and change the conversation on mental health with fundraising for a series of innovative new mental health services," their website reads.
Last October, the Prince and Princess of Wales celebrated World Mental Health Day by interviewing mental health advocates for BBC Newsbeat’s youth-focused radio show.
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During the show, William and Middleton spoke with Emma Hardwell from the charity The Mix, Dr. Abigail Miranda from the Anna Freud Centre for Children and Families, António Ferreria, a mental health advocate, and music therapist Ben Cowley, during which they had a "meaningful conversation about mental health."
During the segment, William urged listeners to build a "toolbox" of techniques to help deal with challenges and mental health-related obstacles.
"A lot of people don't realize what they need until it actually comes along," William said. "You can be living one life one minute and something massively changes, and you realize you don't necessarily have the tools or experience to be able to tackle that."
He continued: "If we can't look after ourselves we're not going to be able to tackle the issues we feel we have to on a day-to-day basis."
