It was twenty years ago next month that The Girlie Show landed on late Friday nights on Channel Four. Replacing the controversial variety programme The Word at a time of rising Girl Power, it was peak ladette - a loud, chaotic cacophony of young women behaving, well, really rather badly as they irreverently interviewed the top celebs of the day, phwoarred over scantily clad male models, and infamously named their "w**ker of the week".

The show also happened to feature one Sara Cox in her first television presenting role. The former model aged 22 became the very personification of a ladette; the sub-culture's poster girl, no less.

But how times change. Three decades later, she's national treasure material - especially since completing her gruelling 135-mile, five-day Great Northern Marathon Challenge for Children in Need last month. Sara raised an unbelievable £11.5million and counting as the nation spurred her on through the punishing hills, dismal weather and nagging injuries. The Prince of Wales was even among her supporters, sending her a video message of encouragement.

Sara, 50, did the equivalent of five marathons in five days so not surprisingly, it came at a physical price - by the end, she couldn't walk. Her legs and feet were so battered and painful that she needed to painfully force on a pair of Crocs because her feet were too swollen for regular shoes.

"It was the maddest, most painful, wonderful thing," she says as she recovers. "While I was doing it, I kept chanting to myself, 'I am fit, I am strong, I'll be home before too long'. And I kept thinking about being in bed with all my dogs and cats with me.

"It was the hardest thing I've ever done. I've never known pain like it but then I've never had eye contact with so many amazing women as I ran along. It powered me on... at the side of the road, in the driving rain, it was bitterly cold, it was wet and filthy and just so many people came out."

She beams at the memory. "The truck drivers honking their horns, the farmers stopping work to come and say 'Hi', the kids by the side of the road, loads of homemade signs... I'm still a bit all over the place but I'm so grateful. It's going to help so many kids. There are children and young people living with chronic pain day in and day out, and I'm grateful that mine is temporary. And I'm grateful that everyone donated so much lovely dosh. It just shows you there's so much good in the world."

Now it's back to the day job for this Bolton-born mum of three - or rather day jobs. In addition to her role as a prime-time Radio Two DJ, Sara's latest TV project is about to air on BBC One - and it's light years away from The Girlie Show. The Marvellous Miniatures Workshop is an eight-part series featuring professional model makers who create detailed miniature replicas of cherished memories and significant cultural moments. Each episode focuses on a different project and blends nostalgia, storytelling and craftsmanship as the team researches, designs and builds intricate scenes for individuals. For Sara, it's a bit of a telly dream come true.

"It's stepping into a world where cherished places from the past are brought back to life in miniature. There's something so magical about things in miniature. They're just so cute," she says.

"But it taps into childhood a lot, too. I had a doll's house when I was little, just a little cheap thing, as well as a tree house that I used to move all the figures around in. There's something so beautiful and nostalgic about it. I also think that humans have always been fascinated by changing the size of something, whether it's the world's biggest Yorkshire pudding that's the size of a swimming pool or a little tiny rocking chair that's created in one of the episodes."

Sara was blown away by the skills of the miniaturist artists themselves. In addition to the tiny rocking chair already mentioned, highlights of the series see them getting to grips with making the world's tiniest Tunnock's tea cakes and also a set of teeny, tiny dominoes.

"It's a bit Honey, I Shrunk the Kids [the 1989 Disney film starring Rick Moranis] and and taps into childhood fancies of being shrunk and being able to adventure through the world into tiny little places. As soon as I heard about the series, I knew straight away it was for me and that I'd love to be involved. I like to think I'm quite creative. I really loved art at school, so I think that's why I'm so fascinated by it. I found it so satisfying and relaxing to watch the experts create the miniatures."

Not that she got to do any miniaturising herself and laughs at the very idea.

"I don't think it would be relaxing watching me do it! I'm not very good with fiddly things. I struggle to even put on a necklace! I always have to get my husband or one of the kids to come and fasten it, so I definitely left model-making to the experts. I was forever tinkering with all these tiny little models on set, though, as the miniaturists brought examples of their past work in. It's endlessly fascinating and just amazing."

In addition to being a magical visual feast, The Marvellous Miniatures Workshop is the screen equivalent of a warm hug - in the vein of that other BBC favourite, The Repair Shop. There's the story of Karim who had a classroom at his secondary school re-created in miniature. Brought up against the backdrop of the National Front in Britain, he suffered racism and abuse, and school was a place of safety for him.

"It was the one place where he looked after during his teenage years," explains Sara. "It sounded like all the teaching staff were amazing at his secondary school but we ended up recreating the classroom of one particular teacher who had a significant impact on Karim. It was lovely to celebrate that and take him back to that classroom." Another of Sara's favourite miniature recreation was a Glasgow tenement where a lady called Sandra spent a lot of her childhood.

"It was the home of her grandparents," explains Sara. "The model really brought a different time to life, showing us a snapshot of a society where everybody knew each other and they didn't feel the need to lock their front doors - a time and place where people didn't have much but they had each other.

"Sandra was so eloquent and was able to tell us so much of her grandparents' story. It's a real tribute to them, especially because her mum died when she was so young. The model is going to be handed down through generations in her family too so it's really keeping a piece of history alive."

Stories like this made filming an emotional experience for Sara.

"When people watch it, they'll see that there's genuine emotion in there, genuine goosebump moments," she says. "I also hope they take away a sense of the social history too and enjoy seeing us bring places back to life again. I want them to get that fuzzy feeling in their belly when they see and hear people's stories, and when we unveil the model at the end and they get to see the beautiful and incredible response from the people the miniatures were made for."

She pauses for a moment. "The comedian Sarah Millican has described this kind of relaxing TV really well. She said, 'It's just like a cup of tea for the soul'. I hope that's the effect this series has on viewers - that they just feel really good when they watch it."

One of the miniaturists made Sara a tiny little garden shed with a teeny-tiny Christmas wreath on it, which Sara loves and has placed on a shelf at home. But what memory or moment would she choose to have recreated in miniature if she could?

"It would be when I was 12 when my dad bought back my childhood pony at Christmas," she smiles. "I'd broken my arm falling off my childhood pony, Gus, but I didn't own him anymore - he'd gone out on loan to somebody else for a while but my dad got him back for me. It was a really mega moment in my life. That morning there'd been lots of whispering and nudging, and then somebody knocked on the door. I went out and Gus was stood there looking all sparkly but also slightly confused because he had no idea what was happening, bless him.

"So, the scene of my miniature would be me, stood there on Christmas morning with Gus all clipped up. He was in a brand-new navy blue and red rug with a red trim and his name on it. The little model of me would have its arm in a sling and Gus would be stood in front of my dad's little whitewashed farmhouse."

Aww. That's definitely one for the second series. But back to Sara's spectacular marathon achievement. A couple of weeks on, how are her legs and feet now?

"I've just been given the all clear by the brilliant physio - it's official, I've not permanently damaged myself with the five marathons," she declares. "I'm proud of my lil' legs."

And we're all so, so proud of you, Sara. If you're reading this Prince William, this lass deserves a Damehood!

• The Marvellous Miniatures Workshop airs on BBC One each day at 2pm, watch all episodes on BBC iPlayer