Kate Middleton Flashes Flat Stomach Three Months After Giving Birth at SportsAid Athlete Workshop

Kate Middleton is back in her J Brand skinny jeans less than three months after giving birth to Prince George. The Duchess of Cambridge, 31, made her second official public appearance since the royal baby's arrival during a SportsAid Athlete Workshop on Friday, Oct. 18. The event was held at Queen Elizabeth Olympic Park in London.

Middleton completed her look with a Smythe one-button blazer, a Ralph Lauren sweater and Stuart Weitzman for Russell and Bromley Corkswoon wedges. Prince William's wife of two and a half years became a patron of the organization in April. The charity helps talented disabled and non-disabled athletes achieve their dreams. Most recently, it assisted in training 20 of the 29 gold medalists from the 2012 Summer Olympics and 27 of the 34 Paralympic gold medalists. Middleton chatted with a group of youths playing wheelchair basketball. She also showed off her sporty side by engaging in a round of volleyball, flashing her flat stomach in the process. The future Queen of England joined 16-year-old Grace Lazard on the court. "She was playing in heels. Whoever plays in heels is amazing," the teen said, according to MSN UK. "She did really well and picked up the sport really quickly. I just feel really privileged and honored to have played with her." Hayley Connor, a badminton coach for SportsAid, tweeted a picture of Middleton at the morning event. "Not your ordinary day - Met HRH the Duchess of Cambridge aka - Kate Middleton," she captioned. "What an amazing opportunity." Middleton is an official patron of eight other charities, including 100 Women in Hedge Funds Philanthropic Initiatives, Action on Addiction, East Anglia Children's Hospices (EACH), National Portrait Gallery, Natural History Museum, The Art Room, The Royal Foundation of The Duke and Duchess of Cambridge and Prince Harry, Place2Be and SportsAid. Prince William coos about Prince George's lion-like "roar" Cathrine, Duchess of Cambridge, Kate Middleton Danny Martindale/WireImage Just yesterday, William hosted his first investiture, presenting awards to individuals recognized for a variety of achievements in the United Kingdom. Queen Elizabeth II typically presides over investitures throughout the year, but her grandson may continue to do them as he transitions into a full-time royal. William presented honors to tennis champ Andy Murray, Vicar Of Dibley producer Jon Plowman, broadcaster Aled Jones and conservationist Helen Butler. Prince Harry, meanwhile, played rugby during a coaching session at Twickenham Stadium in London on Thursday, Oct. 17. Later that afternoon, the royal redhead donned a white coat and goggles as he toured the "Shock Tube" laboratory. The event served as the opening of the Royal British Legion Centre for Blast Injury Studies at Imperial College London