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.”

(Arthur Edwards/The Sun)
Kate joins a training session (Arthur Edwards/The Sun)

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.

Headteacher Despo Stevens spoke about Kate after the visit: “The children didn’t hesitate in showing her affection – that is how they are here – and she didn’t seem to mind at all. I’m sure her mothering instinct came out.”

The Duchess of Cambridge meets local children as she arrives to view the Wimbledon Junior Tennis Initiative at Bond Primary School in Mitcham
The Duchess of Cambridge meets local children in Mitcham (John Stillwell/PA)

Mrs Stevens said she and Kate had chatted about the duchess’ love of tennis: “She said she plays tennis with William and that they’re very competitive, but she didn’t say who wins.

“She said she was trying to play tennis with Prince George and said that he is enjoying some of the extra curricular clubs at school. She also said that Charlotte is enjoying nursery.”

When Kate first arrived she had a private briefing then joined a group of some of the primary’s youngest children in the school hall where they were doing warm-up exercises.

She began by playing the “patter cake” hand clapping game with six-year-olds before a group of older children were ushered in and the younger classmates out – but not before Kate high-fived all the departing tennis hopefuls.

Kate later acted as the mentor of a young girl, using a racket to hit a ball gently along the floor to the youngster who, wearing a tennis mitten on her hand, returned it.

Then with another girl she bounced the ball, encouraging the pupil to hit it with her racket.

When this group left, Kate stood in the doorway of the school hall and shook each of them by the hand, but the handshakes quickly turned into hugs and the duchess told them “well done, well played”.

(Arthur Edwards/The Sun)
Kate hugs the children (Arthur Edwards/The Sun)