Lady Frederick Windsor had a very famous friend make her 40th birthday cake

It's no secret the British royals have friends in high places. From David Beckham and Elton John to Oprah Winfrey and George Clooney, the royals aren't short on A-list chums.

So, it's fitting that when Lady Frederick Windsor celebrated her 40th birthday recently, her cake was whipped up by a famous pal.

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Speaking to Hello! magazine, the sister-in-law of Lady Gabriella Windsor said her at-home celebrations were "a wonderful way to start this decade".

"I also had the most spectacular five-layer birthday cake baked for me by my wonderful friend Jamie Oliver," she added.

"He's so insanely busy; I was so touched."

Lady Frederick, known professionally as Sophie Winkleman, is said to have become friends with the celebrity chef in 2011 while filming Oliver's Food Revolution USA.

Oliver, himself a father of four, was named godfather to Isabella Windsor, Winkleman's youngest daughter with husband Lord Frederick Windsor, 41.

Incidentally, her half-sister Claudia Winkleman, host of Strictly Come Dancing, made an appearance on Oliver's cooking program Friday Night Feast at the start of this year.

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Winkleman married investment banker Lord Frederick — the son of Prince Michael of Kent, a cousin of Queen Elizabeth — in 2009.

However, she had already made a name for herself as an actress in film, stage and television, and has done plenty of radio work.

Her notable on-screen appearances include Peep Show, Two and a Half Men, The Chronicles of Narnia, Hot In Cleveland and CSI: Miami.

Though Winkleman is a lesser-known member of the extended royal family, you might have spotted her on the palace balcony during Trooping the Colour and in some of the recent royal weddings.

She attended Lady Gabriella's wedding to Thomas Kingston in May 2019, and that of Princess Eugenie and Jack Brooksbank in October 2018.

Her eldest daughter Maud was a bridesmaid in both events, and was joined by her younger sister Isabella for Lady Gabriella's big day.

Winkleman admits home-schooling her eldest daughter throughout the COVID-19 pandemic has been a challenge.

"Home schooling I thoroughly failed at," she tells Hello!.

"I couldn't separate my general loathing of kids in front of screens from the fact that Maud needed to be temporarily educated on one."