After passing most of her young life training, preparing and yearning for it, Leona Lewis is finally living the dream. Just as an athlete will dedicate themselves to hoped-for future excellence in their chosen sport, so Lewis has dedicated herself to the idea of one day being both accomplished and lucky enough to follow Whitney, Mariah and Céline into a certain stratosphere of musical superstardom. It’s a slightly old-fashioned dream, given those specifics, rather more Nineties than Now, but having been a child in the commercial heyday of that then ubiquitous trinity of balladeering pop-soul divas, it’s one that she’s grown up with and has cherished. Stage school sign-up aged five. Brit School entrant at 14. The X Factor winner by 21. This latter achievement could have been a poisoned chalice, for few talent-show winners achieve genuine, lasting fame. Lewis, though, is different. She is exceptional, world class.

Here is someone who would have found success in her own time, with or without the Simon Cowell conceived and driven juggernaut that is now an annual tabloid event (last year’s final drew in 12.7 million viewers, while this year’s auditions are claimed to have attracted 180,000-plus hopefuls) and a staple of water-cooler conversation in all but the most high-minded offices. Lewis may have benefited massively from the exposure she gained on The X Factor, but the show is in debt to her, too. The two previous victors, Steve Brookstein and Shayne Ward, can hardly be said to be troubling the national consciousness. Thanks to her subsequent success, anyone anywhere in the UK can at least continue to entertain the notion that they too might have a chance of making it in the music world. Thanks to her example, it’s still possible to believe that a TV show can significantly and permanently change a life, bringing fame, riches, acclaim – the sexy, shiny package that so much of the nation’s youth avidly desires.

But who is she, Leona Lewis? Well, were it not for that rich and thrilling singing voice and the supreme confidence with which she uses it, then you might define her (and in the best possible way) as the most ordinary of girls. She has no discernible attitude, airs or graces. At the centre of her life are her family, her mates and a long-term boyfriend, Lou, an electrician working for his dad’s firm. She loves animals and is a committed vegetarian. She talks with the same sing-songish, everything-sounds-exclamatory cadences and uses the same core vocabulary (lots of greats, amazings and lovelys) as a million other young women whose conversations you catch by chance here, there and everywhere around the capital. But actually, she’s much nicer (it’s the appropriate word) than most of her peers would be if they suddenly found themselves standing in her (always non-leather) shoes.

I say this because clearly she is so utterly, resolutely determined to remain unchanged by all that has happened to her. When I ask if, since suddenly becoming world-renowned, she has caught herself having the occasional diva moment, she sounds genuinely appalled. “It’s just not me. I always remember who I am and where I come from. At the end of the day, all of this [she gestures vaguely above her head, which I take to mean her current multimillion dollar status in the music industry] could be gone tomorrow. Then where would I be left if I’d allowed myself to become a bad person? It’s just not in my nature to be like that. I’m the same me now as I always was.” Which means no mansion in Hampstead, let alone in Hollywood. Lewis says she and Lou are happy still to be living in Hackney. “I like being near my family and his. I like staying in that area. It’s what I know.”

And Hackney is happy to have her there. In fact, so indelibly associated is she with it that the local council has taken to using her image on posters welcoming visitors to the borough. “I’m serious,” she giggles. “They don’t say my name, but just use my picture on these posters. I saw one the other day near Ridley Road market. So funny! Just hilarious.” Would she be the same individual had she not spent most of her formative years there (up to the age of five, she lived in nearby Highbury, Islington)? “I think I’d be exactly the same, ’cos I don’t think it’s where you grow up but who you grow up with that really counts. It’s people who mould you, and for me it’s been Mum and Dad and my friends, all of whom have been lovely and supportive and protective. They were my chief influence.”

In a few minutes’ time she will contradict herself slightly in this regard, saying of her area, “What’s great about it is that it’s so diverse. You find every different ethnic background there, which you don’t in other parts of London. It’s incredibly accepting of cultures other than the white British one [Lewis herself is mixed race, with a Guyanese father and Welsh mother]. My close friends are Turkish, African, Japanese, Chinese; everything. I feel like I’ve experienced and have insight into many different races, and that’s simply through having lived in Hackney for so long ’cos, y’know, everyone there is from somewhere else.” In Leona terms, this last comment represents quite a statement, in that it is reflective about and insightful into her own life. She is far less insightful when reviewing the ways in which that life has changed since finding fame. Everything is just, well, lovely.

This tendency towards starry-eyed blandness is best illustrated by her recollections of having met some of her own female idols, post-X Factor. Receiving the endorsement of the super-influential TV host Oprah Winfrey (in her introductory comments to viewers she described Lewis as being “the real deal”) was, “So great! I mean, I love Oprah! She’s such an incredible lady. So giving, always with time for you. I was, like, really nervous at being invited to make my first American TV appearance on her show, but she was just so nice. And that she said what she said… I was like, ‘Thanks, Oprah!’ So funny.” And meeting Céline Dion? “She was so sweet to me. And when you think of how amazingly talented she is, I mean, how nice is that?” Whitney Houston? “Incredible. It was really brief and she was just like, ‘Hi! How are you? Good luck!’ But it was lovely. Very lovely.”

Repeating her comments verbatim is absolutely not to mock Lewis. Guileless and enthusiastic, she is patently sincere in all she says. But what’s unusual about her at this stage in the game is that sense of her still being a breathless fan with her nose pressed up against the window of celebrityhood. Most other heads would by now have been turned by the sheer scale of their own success and raised profile. For example, her album, Spirit, released last November, topped the charts not just in the UK but in more than 20 other countries, America included. Its stand-out track, Bleeding Love, has already become a classic (rightly, for it is brilliantly conceived and executed), and thanks to it she became only the third British female singer to top the charts with her debut single in that market (following Petula Clark in 1965 and Sheena Easton in 1981). In pop terms, this is all very big stuff indeed.

In the face of it, however, Lewis hangs on to her very ordinariness as if for dear life. No matter that sales of her music are now in the multimillions, or that her PR reps fizz with statistics detailing the global sweep of her appeal. No matter either that she was seen by one of the most mind-bogglingly big audiences in television history when taking part in the closing ceremony of the Beijing Olympics back in August. (Bizarrely, as part of the brief segment in which London showcased its wares, she appeared atop a moving podium singing Whole Lotta Love accompanied on guitar by Led Zeppelin’s Jimmy Page.) None of this stuff seems to destabilise her or infect her with even the slightest degree of celebrity swagger, and for this the credit must go not just to herself but to her parents, Joe and Maria (who also have two younger sons). “They’re both really caring people – Dad’s a youth-offending officer, Mum’s a social worker – but they’re also really driven. Once they had a few fashion shops. He was a DJ at another point, and she a ballet teacher. They’re grounded but go-getting, I’d say.”

What characteristics does Lewis think she has inherited from them respectively? “From my mum? Well, she’s very sensitive and cries easily and I’m the same. If I see a sad advert on TV for the Dogs Trust or some other charity, then I’ll cry, too, ’cos it just affects me so much.” This is not mere sentimentality. Lewis has her principles, and expensive ones at that. She is reported to have turned down a £1 million offer to open the latest Harrods sale because the store sells fur products. She also eschews clothes and accessories made from animal hide and is in talks with Sir Philip Green about creating a range of non-leather bags and shoes for Topshop.

“Mum really loves animals,” she continues, “especially horses, and I definitely got that from her. I ride all the time, and would love to have my own horse one day [she speaks as if still on a waitress’s wage]. Also from her, my self-belief ’cos she’s very like, ‘If you want to do something, then just do it and give it your all.’” And from her father? “Ambition. You know, ‘Set your goals high ’cos all of it is possible.’ That’s very much how I am, too. And from Dad, strength also. He’s someone you can always rely on to be there for you. I’m very much like that with the people who matter to me, there for them whenever they need me.”

Of course, a schedule that now requires her to be in the US, the Far East or elsewhere, often and for long periods, means she is less available to them than before. “Which I feel bad about sometimes. But in these days of e-mail and texting you still keep in touch from a distance. Everybody knows I’m just a phone call away and that they can reach me if they need to. And when I do get time off, it tends to be in blocks, so I’m just back from spending some quality time with three of my best friends. The four of us went to the Algarve and had such a great girlie time in this villa. So funny. It was really rural and cottagey and there were like spiders and everything. You can imagine us running around screaming, trying to catch them under a glass. We had the best week. I’m very family and friends orientated, so really it’s just a question of me managing things in the right way.”

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