The group gave William a card for his wife's birthday, which was made by a group of children, according to the U.K.'s Hello magazine.
Britain's Prince William, a former pilot, flew one of London Air Ambulance's helicopters to mark his appointment as patron of the service's 30th anniversary campaign.
Even before they married, the future King reportedly bought Kate a pearl and garnet rose-gold Victorian ring while they were dating.
Meanwhile, Kate's first royal engagement of the year hasn't yet been revealed.
The designer wrist wear was estimated to have cost over £5,000.
Lexar's world-first 1TB SDXC card is now available for purchase
We've been hearing about 1TB SD cards for a couple of years now, with SanDisk showing off a prototype card back in September 2016. As a comparison, the 512GB version costs US$209.95 (about RM858.69) while the 256GB card is going for US$109.95 (about RM449.69).
Thanking fans for their kinds messages, Kensington Palace tweeted a stunning photo of the duchess alongside the caption: "Thank you everyone for all your lovely messages on The Duchess of Cambridge's birthday".
2008: For her 26th, she and little sister Pippa headed to da club (in pantyhose and a pea coat).
She has had a busy 12 months on the family front, giving birth to Prince Louis last April and becoming a mother-of-three.
Prince William and his wife haven't been out to celebrate the occasion in six years.
Commoners across the United Kingdom have turned their attention away from Brexit and a looming general election to monitor changes to English royal Kate Middleton and her ambiguous baby bump.
She has also been seen out and about over the past couple of weeks, which would be unlikely if she were pregnant.