But when the former winner of a best actress gong in the TV soap awards reveals she was so captivated by the allure of movies she'd sprint in the direction of outdoor camera lights, you know this is one very single-minded lady.
"I've always known I wanted to be in the business," says the actress/singer who starred as sparky Jo Sugden for three years.
"Aged five, in primary school, I said to my teacher I wanted to be an actress on TV and film. And I wrote a school project about that which my mum kept.
"When I was a little older I used my Christmas notepaper from my grandma and wrote to the Spice Girls, to Cilla and to Coronation Street, to ask how I could get started in showbiz. Corrie wrote back and said 'Get an agent' – and I was so excited at receiving this Granada letterhead reply that I kept it under my pillow."
Roxanne, who grew up in Carlisle, had that unshakeable belief she would one day make it as an entertainer.
And it paid off. Since leaving Emmerdale in 2008, she has appeared in a range of TV dramas such as Casualty and Waterloo Road, and theatre roles.
Now, she has joined the cast of cult musical The Rocky Horror Show, playing the lead role of Janet Weiss, who becomes caught up in all sorts of sexual madness – in a fun sort of way.
"I've not seen the show," she admits of Richard O'Brien's cult hit which has now run for 40 years. "I didn't want to look at it because I didn't want to copy or imitate. I wanted to find my own Janet. I see her as a wholesome, all-American girl who prepares dinner and does the washing up with her mum. Yet, she wears the trousers in the relationship."
Roxanne, 30, reveals she watched a lot of sixties-based TV and film, the likes of Mad Men and Doris Day movies to gain an understanding of women of that era.
"You have to try to embody the mannerisms," she informs. "I watched how Mad Men's January Jones held her posture, how she walked and sat down.
"It was all so deliberate, always on show. The real feelings were kept underneath."
Roxanne's mum watched her daughter appear on stage as Janet – and was stunned to see the transformation.
"After she saw me on stage she kept saying 'Last night you were in your onesie eating sweets. Now, you're a sixties woman.' But if you can surprise someone you've known all your life, it's great."
Roxanne's mum has played a huge part in her girl's success.
"I was raised by my mum and grandma," she says. "My mum used to be an air hostess but then went on to work shifts in a factory to make sure we survived. But things were tough.
"I loved musicals and my grandma would help me make cassettes, so I could wake up to Tina Turner or Olivia Newton John. And we'd watch Saturday Night Fever or whatever on TV, but our telly had a battery, and sometimes the film would fade during the screening."
Mum and grandmother couldn't afford to send Roxanne to stage school, but they made sure she went on to university, graduating in Media and Cultural Studies in Liverpool.
At weekends she studied at the Manchester School of Screen Acting, auditioning whenever an opportunity emerged.
"If I had a pound for every audition I've done, I'd be a millionaire," she says grinning.
She was mad keen. One night, while leaving university, she saw floodlights in a street near the Liverpool FC ground and realised filming was taking place.
"I immediately ran in the direction of the lights," she says, laughing, realising the action was a metaphor for her life.
"And I discovered Ricky Tomlinson was making the football movie, Nice Guy Eddie. I asked if I could hang around and watch and Ricky said 'Of course, love'. He was so nice in real life."
She adds, with a knowing grin: "In life you either walk past or run over to have a look. And I always had a look. But it took me five years of being told 'No' before I got me a 'Yes.'
Roxanne began with a career in music breaking into acting. The 5ft 1in stunner has since appeared on the covers of several lads mags, but she won't talk about personal relationships ('You've got to hold something back, stay low-key') or chase fame for the sake of it.
"I didn't start out to be famous," she says. "I wanted to be an actor. I get asked every year to go into the Jungle or Big Brother, but no matter how much money they offer, I won't do it. There's a lack of dignity attached to these shows."
Roxanne believes showbiz should be about hard work and talent.
"If you get it easy you don't appreciate it. And I still cry when I don't get a job. Yet, there's nothing like the phone call to hear you've got the part."
Especially a role such as the repressed Janet.
"She's a blonde, a ring-on-the-finger-and-kids sixties compliant woman and I'm brunette and feisty," says the actress. "It's the perfect part."
l The Rocky Horror Show, The King's Theatre, February 25 to March 2.