The Duchess of Cambridge joined a tennis training session for the Wimbledon stars of tomorrow - then joked how she is less "sporty" with two children and a third on the way.
Kate, showing little sign of her pregnancy, donned a smart tracksuit and let her hair down for her afternoon with primary school children from south London.
With a huge smile on her face and bags of encouragement, the royal, who is a passionate tennis fan and patron of the organisation which stages the Wimbledon Championships, threw balls, chatted with the children and added an element of excitement to their tennis session.
At the end of the training, pupils and staff of Bond Primary School in Mitcham gathered in the sports hall and the duchess told them: "A big thank you from me as well because I've loved playing with you all - it's so energetic and exciting to be part of it, so well done for all the hard work.
"And I love tennis, I think it's a great sport, I was really sporty when I was little, less so now that I've got lots of babies."
Kate patted her small baby bump and smiled as she said the word "babies" and her audience laughed.
She ended by saying: "But keep it up, it's great to be active, as everyone's been saying here today. It's been a real pleasure to meet all of you."
The youngsters at Bond Primary were receiving training sessions under the Wimbledon Junior Tennis Initiative - the outreach programme of the All England Lawn Tennis and Croquet Club, which Kate supports as patron.
Earlier during a visit to Great Ormond Street Hospital to open the latest phase of a redevelopment project, Kate was presented with cuddly toys for Prince George and Princess Charlotte, adding to the generous gifts the children received in 2017.
Kate received the two presents - called Bernard and Wendy - from nine-year-old Ava Watt, who is a regular patient at the hospital and has cystic fibrosis.