Prince George is "fascinated" by fencing and Princess Charlotte loves horse riding.
Duchess Catherine has revealed her and husband Prince William's three-year-old son is a big fan of the fast-paced sport because he loves the head guards the athletes use, and their 17-month-old daughter loves getting on a horse.
While speaking to equestrian gold medallist Natasha Baker, the 34-year-old duchess said: "George is fascinated by fencing but I think that's because of the face shields.
"Charlotte would have loved to be here but she'd be running riot!"
Natasha later revealed she had a good chat with Catherine about Charlotte's love of horses.
The Paralympian told the Daily Mirror newspaper: "I asked her how the children were and she said Charlotte is really enjoying her riding which is great to hear and I said we may see her here on a line-up in 20 years time.
"She emphasised that Charlotte has this passion about horses and although she doesn't echo it, she'll do her best to champion and encourage it."
Catherine met Natasha at a Buckingham Palace reception for all of Team GB and ParalympicsGB's medallists from the Rio 2016 Games.
Like Charlotte, Queen Elizabeth is also a big fan of horses and she enjoyed a chat with show-jumper Nick Skelton at the event.
He added: "You don't need to give the Queen any advice, she's very knowledgeable about all equestrian sports. She can tell me a thing or two!
"What's so nice is to see so many of the royal family here tonight."
William, Prince Harry, the Duke and Duchess of Gloucester and the Duke of Kent were also at the event.