She was never the most raucous member of Girls Aloud. Neither was she considered the most popular, pretty or column-worthy. And blighted by a crippling lack of confidence, brought on by constant criticism, Nicola Roberts was happy to hide on the sidelines and let her more self-assured band mates take centre stage.

But not any more. Over the past couple of years, she’s overhauled her image and carved out a name for herself as a style icon and beauty guru. All while quietly cracking on with writing the music that has landed her a lucrative solo record deal and impressed some of the toughest critics in the business.

The release of her debut single, Beat Of My Drum, an imaginative pop song fizzing with energy, is finally her chance to shine.

Don’t be fooled by her fragile exterior, though – the strong-willed, feisty redhead here today is a million miles away from the shy teen whose spirit was crushed by taunts from those who didn’t deem her beautiful enough.

“I don’t care what they say now,” she says, firmly. “It’s too mentally draining for me to be bothered. This is how I was born and I’ve got bigger things to care about than shallow people’s opinions of me.”

Nevertheless, the pain from those early days is still raw. Sticks And Stones, one of the tracks on 25-year-old Nicola’s album, Cinderella’s Eyes, out later this year, is particularly personal, with lyrics like: “How funny that I was too young for so many things, yet you thought I’d cope with being told I’m ugly over and over – I’d read it, believe it, said no to the shrink. I can fix it, I think…”

Nicola admits now that she’s dreading singing that song live for the first time, for fear of breaking down.

“When you open a wound, it takes you back to what it felt like. The lyrics came naturally, so it was impossible for it not to be personal. I didn’t want people to just see the surface of me. And I think I’ve deleted a lot of the bad times. I’ve chosen to block them out and leave it all behind,” she says.

“They can’t hurt me now – you harden to it. In order to keep myself protected, I’ve had to toughen my heart a little bit, which is a real shame. But I don’t feel sorry for myself. I just feel embarrassed for the people who wrote and said horrible things, knowing I was a 17-year-old girl. I would never choose to be cruel to anyone, it’s just not in me.”

There was a time when, desperate to conform, Runcorn-born Nicola considered drastic measures to change her looks. “I used to absolutely hate my nose beyond belief, and a few years ago I thought about getting it done,” she recalls. “But that bump is part of me – all our imperfections make us who we are.”