It's been 15 years since Lady Frederick Windsor married into the "warm and supportive" royal family and, like her relatives, she is grateful to be given a platform to champion the issues she is passionate about.
"It's a such a privilege to be able to talk about something you care about and for people to listen," says Lady Frederick, who joined HELLO! for an exclusive interview and photoshoot to talk about her work with The Big Issue Group, which recently launched its Big Community initiative - a series of Community Roadshows, the Big Issue Membership scheme and a new policy call, Poverty Zero.
"I talk to every homeless person I pass. I find it sad when people simply walk past homeless people.
"It doesn't matter if you don't have any cash to spare; just communicate so they don't feel invisible - even just a supportive smile," adds the actress, who is known as Sophie Winkleman professionally and joined vendors on the streets of London earlier this year to sell copies of the magazine.
Close royal ties
Sophie, 44, also praises her "warm and supportive" royal relatives – including the King and the Princess of Wales.
"She's wonderful," she says of Kate. "I last saw her at Wimbledon; it was so cheering to see her, beautiful as ever. She's been amazingly brave and is doing so well."
She is equally fond of the King, who is back at work following his own cancer diagnosis.
"Duty and service run through him like a stick of rock; it just doesn't occur to him to rest, something which those who love him are desperate for him to do," she says. "He's battling cancer and doesn't give himself a moment off – he's a hugely inspirational man.
"The central royal family work very hard. It's not an easy existence, having a spotlight on you from the second you're born. I count pretty much every one of them as a trusted friend. I'm very lucky."
Romantic first encounter with husband Lord Frederick
The Sanditon and Belgravia: The Next Chapter star, recently celebrated her 15th wedding anniversary with her banker husband Lord Frederick – son of Prince and Princess Michael of Kent – whom she met because he recognised her from her role as Big Suze in Channel 4 comedy Peep Show.
"We left two different parties and went for the same taxi," she recalls. "He said, 'You're Big Suze, I love you!' I laughed and asked the cab to take me somewhere. He pretended he was going to the same place, we shared the taxi and we've been together ever since."
Family life with daughters
The couple share two daughters – Maud, 11, and eight-year-old Isabella. Sophie, who doesn't have any social media accounts and won't allow the girls to have them either, shares her strong views on the subject.
"The poor girls - there's nothing less cool than to have a mother who's campaigning against smartphones," she laughs. "But at some point, I hope they'll realise what I'm trying to do.
"I don't believe that any child should have a device with access to the internet before they're 16; they see violence which permanently distorts their minds. Platforms like Instagram make young girls hate themselves and apps like TikTok and Snapchat totally destroy the concentration span."
To become a member of the Big Issue, visit bigissue.com/membership.
To read the full exclusive interview, pick up the latest issue of HELLO! on sale in the UK on Monday. You can subscribe to HELLO! to get the magazine delivered free to your door every week or purchase the digital edition online via our Apple or Google apps.