The Duchess of Cambridge celebrated becoming joint president of The Scout Association in true Scout-style – by toasting marshmallows around a campfire.

Kate was also awarded the youth movement’s top prize – the Silver Wolf Award – on the recommendation of the chief scout, adventurer Bear Grylls.

The duchess, casually dressed in brown trousers, boots and a gilet and her Scout scarf, joined the 12th Northolt Scout Group in west London on Tuesday to mark her new role.

A passionate advocate of the benefits of children spending time outdoors, she proved an expert marshmallow toaster over the campfire.

“Make sure it doesn’t get gooey and fall off,” she told the youngsters.

As she sat with the Cub Scouts on socially distanced tree stumps around a fire pit, the duchess asked: “Are you having fun? How many marshmallows have you eaten?”

When they replied one, she remarked: “Oh my goodness, that’s so controlled of you. Is that because there’s only one in your bag?”

Toasting her marshmallow before taking a bite, Kate said: “You must have missed this.”

The children told the duchess they had been holding Scout camps at home during lockdown.

Some camped in their back garden for two nights or even the living room, and one used a bath.

Kate heard how the association adapted during the pandemic when sessions went online as part of #TheGreatIndoors campaign.

Her visit was also to thank the organisation’s volunteers for supporting more than half-a-million young people during lockdown.

Speaking to Beaver Scouts while cutting out and decorating whirlybirds, she said: “It is a shame you haven’t been able to go on any camps. It has been hard to get out and see your friends.”

After her whirlybird fell to the floor, she said: “I don’t think I’ll get full marks.”

The Cub Scouts told the duchess they had sent handwritten cards to elderly people and those shielding during the pandemic.

They also penned messages on pebbles.

Kate said: “That’s a really lovely idea. It has been hard as no one can see each other. But these are really special. Well done you.”

This year, Scout groups across the UK have carried out more than 10,000 acts of kindness by sending cards and greetings to care home residents.

The duchess is sharing her new joint role – her first presidency of an organisation – with the Queen’s cousin, the Duke of Kent, who has been president of the youth movement since 1975.

The Silver Wolf, which the Duke of Kent also has, is usually only awarded for 30 years’ service, but is in the gift of the chief scout, and is the highest prize for adult volunteers.

Kate remarked: “I will wear it with pride.”

The duchess was previously a volunteer with a Cub Scout pack when she and the Duke of Cambridge lived in Anglesey, North Wales.

She has carried out numerous visits to Scout groups over the years, including joining Cubs in North Wootton, near King’s Lynn in Norfolk, in 2016 to celebrate 100 years of the youth movement and visiting the Scouts’ headquarters in Gilwell Park in Essex in 2019.

Matt Hyde, chief executive of the Scouts, and 10-year-old Aisha, presented the duchess with her Silver Wolf Award, saying afterwards: “Everyone in the Scout movement is overjoyed that the Duchess of Cambridge is to become a joint president.”

TV presenter Grylls, who could not make the event as he was filming in the US, launched The Great Indoors in March.

Kate described her delight at becoming joint president in a statement, saying how when she first volunteered she was “struck by the huge impact the organisation has on inspiring young people to support their communities and achieve their goals”.

The Duke of Kent welcomed Kate to the role, saying: “The Scouts’ ethos of dedication, inclusivity and lending a helping hand wherever one is needed resonates across the generations and, as such, I am delighted to welcome the Duchess of Cambridge as joint president, and to work together to continue that legacy.”

The Queen is patron of The Scout Association.