Tennis coach Judy Murray has a new rival to keep an eye on - the Duchess of Cambridge.
Kate joined dozens of Edinburgh school pupils and teachers as they were taught how to coach and pass on the basics of tennis to children at a clinic hosted by Ms Murray in the Scottish capital.
Often seen in the royal box at Wimbledon and described as a "keen" tennis player, Kate showed off her skills as those taking part were challenged to balance and spin a racket at Craigmount High School.
The class was part of the Tennis on the Road project created by Ms Murray in 2014 with the aim of capitalising on the success of her sons Andy and Jamie by increasing coaching capacity and growing the game at a grassroots level across Scotland.
Speaking after the event, Ms Murray said Kate's participation in the class was "fantastic for tennis and women's sport".
"She said she'd love to come back and do some more," Ms Murray said.
"From a parent's perspective, I think she was really interested in what she could pass on to her children.
"She asked me, 'at what age can a child hold a racket?', and I told her that with children of George's age you can start with a balloon and just the hand and then go on to make it gradually smaller and doing the right thing at the right stage."
She added: "I don't know if he has played yet but she was certainly asking. If you start simple and a child can do it then a child enjoys it and everything grows from there."
Despite teaching sons Andy and Jamie all about tennis, Ms Murray said she will not be pushing a racket into the hands of her new granddaughter Sophia.
Ms Murray - a former contestant on Strictly Come Dancing - joked: "No, I'm going to teach her how to dance."
The 56-year-old was tight-lipped about the new arrival to the Murray family, but did say she was "very proud" to be a gran. Andy's wife Kim gave birth to their first child on February 7.
After learning about the coaching, Kate passed on tips and advice to seven and eight-year-olds who joined the class to try tennis for the first time.
The youngsters seemed oblivious to who Kate was and celebrated with the Duchess when her team won a race at the end of the class.
Ms Murray said: "I know she loves sport and she obviously has great people skills and has children so I thought she would fit in very easily and be interested in what we do - and she was."
Before swapping her high heels for trainers, the Duchess - known as the Countess of Strathearn in Scotland - visited two school-based charity projects in the city linked to causes close to her heart.
She began by taking part in a sing-a-long during a visit to St Catherine's Primary.
The school is one of 28 in Scotland where counsellors from children's mental health charity Place2Be are on hand to support pupils having difficulties.
Charity patron Kate met teachers to discuss the programme after singing along to Welcome Everybody at an assembly where youngsters presented her with a quaich, a Scottish toasting cup.
She told pupils: "I think everybody should start their morning like that."
Kate, who wore a forest green Max Mara coat and a skirt by Le Kilt for the occasion, later spoke to pupils gathered outside the school.
Sophie Winters, eight, said: "She said we sang really well."
Kate, who was carrying out her first solo set of official engagements north of the border, then travelled across the city to Wester Hailes Education Centre to see work being carried out by The Art Room.
The charity, of which she is also patron, set up its first Scottish studio at the school in 2014 and works with children to increase their self-esteem, self-confidence and independence through art.
She was greeted by cheering pupils in the school playground before going inside where an art session was being held.