The Princess of Wales has a very special reason to celebrate today [Wednesday] following her summer break.
Kate's sister, Pippa Matthews (nee Middleton), turns 40 on 6 September and no doubt, the royal will make a big fuss of her younger sister.
Pippa and her husband, James Matthews, have been enjoying a late summer break in Lake Como, Italy, where they attended the wedding of nutritional therapist Belle Porter and Max Robinson.
The author and columnist married hedge fund manager James in May 2017, and the pair share three children – Arthur, four, Grace, two, and one-year-old Rose.
Pippa shares a close bond with her sister and future Queen Kate, having once shared a flat together in Chelsea, London, after they had both graduated from university.
The Princess, now 41, chose Pippa to be her maid of honour on her wedding day to Prince William in 2011, and she returned the favour at her little sister's nuptials. Take a look back at Pippa's starring role at the royal wedding in the clip below...
Pippa, James and their three young children reside in a £15m property in Berkshire – close to Pippa's parents, Carole and Michael Middleton, and her younger brother, James Middleton and his wife, Alizee Thevenet.
Meanwhile, William, Kate and their three children, Prince George, Princess Charlotte and Prince Louis live at Adelaide Cottage in Windsor – a short drive away from Kate's parents and siblings.
© GettyIt's not known whether Pippa will throw a party for her milestone birthday, but no doubt the family will get together to celebrate.
Kate, who is patron of the Rugby Football Union, will attend a group stage match between England and Argentina at the Stade de Marseille on Saturday – the first weekend of the Rugby World Cup.
Mum-of-three Pippa previously worked part-time for her parents' party supplies business, Party Pieces.
© GettyThe company, which was founded by Carole in 1987, was sold to entrepreneur James Sinclair in June, after falling into administration.
Pippa also penned a book, Celebrate, a one-stop guide to entertaining, in 2012.
All about Pippa Middleton
Philippa Charlotte Middleton was born on 6 September 1983 at the Royal Berkshire Hospital in Reading.
She is the second child of former flight attendant Carole Middleton and former BA flight dispatcher, Michael Middleton.
© GettyHer elder sister is the Princess of Wales (formerly Kate Middleton) and she has a younger brother, James Middleton, born in 1987.
Kate and Pippa grew up in the small village of Bradfield Southend in Berkshire, before the Middleton family moved to Amman, Jordan in 1984, where Michael was based for work.
They spent two years in Jordan, before returning to the UK, where they moved to Bucklebury Manor.
© GettyPippa was educated at St Andrew's school in Pangbourne and Down House school in Cold Ash. Like her older sister Kate, she was also a boarder at Marlborough College.
She went on to study English literature at the University of Edinburgh.
Pippa briefly worked in public relations and wrote a fitness and wellbeing column for Waitrose's magazine.
© GettyIn 2022, it was revealed she had earned a postgraduate master's degree in Physical Education, Sport and Physical Literacy from University of Wales Trinity Saint David.
Like her sister Kate, Pippa shares a passion for sport and has taken on a number of challenges, including a 3,000-mile cycling race across America, the Bosphorus Cross-Continental Swimming Race - a 6.5 km swimming competition in Istanbul and a 47-mile swim-run competition in Sweden.
