WHO'D have thought it?

Tracy Beaker has become a bad girl, determined to show her sexy side to the world.

But that's what happens when actresses such as Dani Harmer leave the cosy world of CBeebies and make their way in the world of adult entertainment.

Dani, now 24, has joined the cast of the Rocky Horror Show, playing Janet Weiss, which comes to the King's Theatre next month.

And in case you've been kept captive in a castle for the past 40 years since Richard O'Brien's camp classic was created, here's Janet's story.

She's an all-American innocent who is pulled into the world of sexual madness and deviation. How does she cope? Well, she switches sides – and become something of a vamp.

So how does someone who's been seen as the cutesy face of kiddy TV turn into a suspenders and basque-wearing temptress?

"Quite easily," says Dani. "I'm just loving the chance to put across a different image.

"To be honest, I was nervous about how the audience would take it, having never seen me in my underwear before, but the reaction has been great."

Dani was a child star before Tracy Beaker. Her showbiz career actually began at the age of six, in the original West End production of The Who's rock opera, Tommy, playing the four-year-old version of the Pinball Wizard.

"Yes, I started my career as a boy," she laughs. "And I loved it. I got to meet Roger Daltrey and Pete Townsend from the Who, so it was brilliant.

"I wish I could go back and do it all again because now I'm a massive Who fan. Back then it was all a bit lost on me. But my dad was in his element."

Dani wasn't a typical stage school kid. She says she found the experience 'a bit weird' because she wasn't a 'jazz hands' sort of child.

But she has talent nonetheless, which took her into Tracy Beaker world and fame.

However, it's a connection she's keen to sever.

"Tracy Beaker is fading from TV viewers' memories. And people know how old I am so it's not really an issue."

Part of Dani's reinvention came in the form of her appearance on Strictly Come Dancing in which she samba'd her way into the adult viewing consciousness.

"It was the most fantastic experience of my life," she says. "I met some amazing people, had a great four months, and then went out on the tour.

"The pressure was always enormous, when you know you're going out every week in front of four million people, but you've got just to relax and enjoy it."

Dani enjoyed television, but maintains she still loves the thrill of appearing live on stage.

You get nervous before every show, but you also get the audiences so that's great fun."

And how can it not be fun appearing in the Rocky Horror Show?

"It's a show you can never get bored of," she enthuses. "I first saw the show in Cardiff when I was 13, and I became a massive fan. I used to dress up for it and here I am back playing Janet, and it's a bit bizarre.

"I was really nervous when I first started but I've got over that now."

Dani adds: "We've been on the road for nine weeks now. You never quite know what the audience will do on any night, so that keeps it alive."

It's clear Dani has a professional life after Tracey.

"I want to do everything, stage, TV, and keep going for the next 60 years," she says, in determined voice.

"And I know the business is tough, but it's always been tough. You've just got to keep going, and take risks."

Even if it means appearing on stage in your undies?

"Even underwear," she says, grinning. "But I've got quite a thick skin."

l The Rocky Horror Show, The King's Theatre, August 6-10.