Royals British Royal Family Prince William Hit the Pub for 'Low-Key' Outing with Mother-in-Law Carole Middleton amid Kate's Cancer Treatment The Princess of Wales' parents, Carole and Michael Middleton, have been a constant support in recent months By Janine Henni Janine Henni Janine Henni is a Royals Staff Writer for PEOPLE Digital, covering modern monarchies and the world's most famous families. Like Queen Elizabeth, she loves horses and a great tiara moment. People Editorial Guidelines Published on April 11, 2024 03:50PM EDT Prince William at the Commonwealth Day Service on March 11, 2024; Carole Middleton at Wimbledon on June 29, 2022. Photo: Max Mumby/Indigo/Getty; Karwai Tang/WireImage Prince William may have recently raised a glass with his mother-in-law, Carole Middleton. The Prince of Wales, 41, and his wife Kate Middleton's mom grabbed a drink at a local pub over the weekend, according to an April 10 report from Richard Eden of the Daily Mail. "It was all very low-key with no great fanfare. He just walked in and through the pub. He appeared to be with Carole Middleton," Eden quoted a patron as saying. Prince William and Princess Kate have kept a low profile since she announced in a self-written speech on March 22 that she is undergoing treatment for cancer. The Princess of Wales, 42, explained that the diagnosis came after post-operative tests following her abdominal surgery in January. Carole and Michael Middleton attend Kate Middleton's Christmas concert on Dec. 8, 2023. Mark Cuthbert/UK Press/Getty Prince William Returns to Social Media with Personal Message amid School Break with Kate Middleton and Kids A source previously told PEOPLE that Kate’s parents, Carole and Michael Middleton, "will be there to lend support" following her abdominal surgery. On March 4, the Princess of Wales was seen for the first time following her surgery. In photos obtained by Backgrid, she sat in the front seat of a car that Carole drove. The Middletons live a short car ride away from the Prince and Princess of Wales' home in Windsor and are a constant presence in their grandchildren's lives, often having Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5, over for sleepovers. "Her parents are an enduring factor in the upbringing of their grandchildren," a palace insider said. "And they will be a reassuring presence when she goes back to Windsor to recuperate." Carole Middleton and Kate Middleton attend Royal Ascot in 2017. Max Mumby/Indigo/Getty How to Send Kate Middleton a Card amid Her Cancer Treatment (and You Might Get a Royal Reply) Princess Kate’s siblings Pippa and James also live nearby, and her younger brother shared a touching statement on Instagram following her cancer news announcement. "Over the years, we have climbed many mountains together. As a family, we will climb this one with you too," he wrote below a photo of them as children. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Kate Middleton and Prince William in Wales on October 3, 2023. Samir Hussein/WireImage As she focuses on her health, Princess Kate can also lean on Prince William. "He is a very reliable, strong person. She doesn’t feel isolated in this because of William, who is right beside her," a longtime family friend exclusively tells PEOPLE. The Princess of Wales mentioned in the video message announcing her cancer news that her husband of nearly 13 years is "a great source of comfort and reassurance." "This is about supporting her and her feeling supported. It is a joint effort. She doesn’t feel isolated at all," the insider says. "The nuclear family that they have created so well is an immense support not only to him but to Catherine too."