In her 30-odd years on the stage, Juliet Cadzow has notched up several claims to fame. Her first professional engagement was with Billy Connolly, in The Great Northern Welly Boot Show, and she has performed everywhere from the tiniest community centre to Edinburgh’s Festival Theatre. As Balamory’s irrepressible bus driver Edie McCredie, her admirers range from toddlers to young men who should be deep in Finnigans Wake instead of watching children’s television. But perhaps her most extraordinary conversation-stopper is that Cameron Stout, the Big Brother winner and Scotland’s most famous virgin, has seen her in the nude.

True, it may have been about 15 years ago, and it may have been on a slab in a graveyard in Orkney, but it happened all right.

“He was one of the cheeky wee boys peeping out from behind a gravestone,” laughs Cadzow, who was filming Venus Peter on the island at the time. “There are not many women who can say that Cameron has seen them naked.”

At 57, Cadzow’s career has jumped aboard a speeding daisy bus. Having spent most of her working life at Dundee Rep, the Lyceum and the Traverse, as well as a 10-year stint in London, she was far from enthusiastic when her agent rang in early 2002 to suggest that she audition for a part in a children’s television series. But her family’s fortunes were not in good shape: her husband David Maclennan had been involved in a long, acrimonious dispute with Wildcat Theatre Company and she had nothing particularly pressing in her diary.

So she went along, sang Ally Bally Bee, told a story about sheep rustlers and didn’t expect to hear from them again. Then she was called back. By this time the BBC were describing Balamory as “a children’s soap” and planning 40-plus episodes. Cadzow changed her mind about the job. “I’d seen the sets and some scripts. I thought, wow, this is quite something.”

So it was just as well that the part of Balamory’s first lady of the internal combustion engine was hers. She joined Julie Wilson Nimmo (previously best known as Mrs Greg Hemphill), the mad-haired comedian Miles Jupp and the rest of the rainbow alliance that populates the fictional village, and set off for Mull.

In the intervening two years, Tobermory’s distinctive cottages have become a highly desirable pre-school holiday destination, a Tenerife for toddlers. Back then it was still a rainy little island, until a busload of thespians arrived.

“We had all recorded our songs in the studio in Glasgow,” Cadzow recalls. “Then off we went up to Mull. We were each taken to a different coloured house and asked to sing our songs to play back. In the street. With the locals all watching us. Archie was first and he came back ashen, saying, ‘I’ve just had this dreadful experience. I had to dance in the street to my song’.”

When it came to Cadzow, she had to summon up all her professional reserves. “I was somewhere between bashfulness and embarrassment, standing there with the director egging me on, doing lots of Bali Hi movements.” She gives an exuberant demonstration.

These days, Cadzow has become accustomed to bursting into song in a shopping centre and signing autographs. Balamory has become a success on a scale nobody could have anticipated. It quickly moved from the CBeebies digital television channel to BBC1. With more than 150 shows already made, there is talk of one last series, to take the number of episodes to the magic 200 that guarantees a children’s series can be repeated for ever.

It is big business: Balamory is sold to more than 100 countries and is broadcast to in excess of 20m households worldwide. There is a wonderful BBC website, as well as DVDs, colouring books, rag dolls, PC Plum’s rescue radio and a build-your-own Balamory set.

This festive season, the marketing reaches its logical conclusion with the Balamory live show. Cadzow is used to playing in small theatres, yet here she is, preparing to play in venues that rock bands have difficulty selling out, in a show that has a five-minute pause before the first words are spoken. The director reckons that’s how long it will take the kids to stop cheering and clapping and bouncing out of their seats.

“It’s as if a star shone down with a little sprinkling of fairy dust,” says Cadzow. “Your dream is to be in something successful: a West End show, a television series, a hit movie. To have this huge success at this stage in my life is wonderful.”

Then there is the adulation of the fans, who are not all still in training pants. “I am quite a cult with the students,” she says. “ I walk past and they sing Baaal-ah-moray. My jaw hangs open when I think about it.”

Balamory: What’s the Story is performing today at 11am and 2pm at the AECC in Aberdeen, and at the SECC in Glasgow from December 27 to January 4. For tickets call 0870 013 4060, or visit www.balamory.com

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