When I arrive at the central London hotel where I am to interview the woman who is Supernanny, I find her deep in discussion with her public relations person. They are poring over her schedule, which is printed out on a series of A4 pages.
"And what's this?" Jo Frost says, pointing at what looks suspiciously like a gap in proceedings.
"That's nothing," the PR says, meaning it literally. "It's free time."
Frost huffs. "Well, no point in that. If we can fill it, let's fill it. Have you called Closer and Heat? Phone up the editors there; they've always been big supporters."
Presently, we are introduced. Her handshake is firm, but her gaze is elsewhere. I compliment her on a tan the colour of mahogany, but she ignores this and turns back to her PR. "What time do I have to be at Richard & Judy?" she says.
Only once her schedule is padded out to her satisfaction does she give me her full attention. Suddenly now, there is a smile, which cracks the make-up and lightens the eyes until she appears almost friendly. But she is all business today, here to plug a new book and TV series, and also to further, as she will later reveal, the brand.
(Before we hear from her, a word of warning: Frost does have a rather unusual command of the English language, often making words mean whatever she wants them to, even if the dictionary has other ideas. She can also bend sentences out of all discernible shape.)
"When I say brand," she begins, stirring milk into a cup of tea, "it's because I'm aware that's how it is. Supernanny, Jo Frost. Same thing. People know me as Jo Frost, don't they? Supernanny. But this now is me talking about the whole of the childcare experience." She is referring to her new book, Jo Frost's Confident Baby Care. "The Supernanny books [there have been three to date] were TV tie-ins, but this one is all mine: all new, my advice, my knowledge. It took me nine months to write."
And it heralds a certain departure for the woman who has become so very identified with the taming of tearaway toddlers. Should we read something pertinent into the fact that she has now gone back to the beginning of a baby's life?
"It isn't me going back at all," she counters. "I've been a nanny for 17 years and I've never just looked after one particular age group. For me, it's always been generic, and this book is a fantastic opportunity for everybody because it allows parents from day one to be confident and make decisions in order to raise awareness about the choices they are going to make and how to involve everything else on top of that, so it's really going back to the very beginning."
Which is sort of what I said, no?
"Well, I've still to do that, actually. That is yet to come, definitely yet to come. There will be more books. But I do believe that it starts at the beginning because the beginning is, you know, when you first have a child. Do you know what I'm saying?"
Not for the last time this morning, Jo Frost has completely lost me.
Three years since its inception, Supernanny has now become a global institution, and a show that is screened in 48 countries (in the US, Frost is an Oprah-endorsed megastar). It certainly makes for compulsive viewing, with our designer-labelled heroine effectively a one-woman cavalry arriving to help hapless parents having to deal with a multitude of childcare nightmares.
"Parenting isn't easy, it isn't, and we are all of us this far away from making all kinds of mistakes," she says. "Some of the people I've worked with have had it really hard. Some have even approached social services for help before I came along..."
Frost insists she has little to do with the vetting process itself, and simply requests of the show's production company, Ricochet (which also produces It's Me or the Dog and Justin and Colin's Home Show), that each family is sufficiently different from the one the week before, "so that I can implement new skills and teach more people more ways to cope". Frost mentions Ricochet a lot during our conversation. She clearly wishes to make the distinction that the programme's reliance upon image – Frost as dominatrix, effectively – was their idea, not hers.
"Though actually," she points out, "the glasses were mine, and I do happen to wear lipstick and black eyeliner. But, yes, it was Ricochet who wanted that whole look. And really, you know, you can't knock it. It was very clever of them. They thought the power dressing would distinguish me immediately, and it did."
It also broadened her appeal, reaching sections of society not normally interested in childcare.
"It did bring me a certain fanbase, yes. I got letters." She shrieks loudly. "Oh God, am I being diplomatic with that conversation? But no, seriously, let's face it, there are men out there who are attracted to suits and heels, right?" And did it titillate her to learn this?
Contradictorily, she now says: "It's not something I'm even aware of, and for me it wasn't relevant."
But perhaps it was, for now she has implemented an image change. The photograph that adorns her new book features a softer Frost, sans glasses, with less make-up and flowing hair, cradling a baby upon whom she gazes lovingly. Can this really be the same woman whose last book cast her as a sneering finger-wagger?
"People have taken that image and linked it with me having the same personality," she says, "but I want everyone to know that I have another side. I can be very girly. I like those smelly candles, for example."
Good to know. And, she adds, she laughs; she laughs a lot.
"Oh, I'm always laughing with the children in Supernanny, but you don't see it because Ricochet decide what to leave on the cutting-room floor and what to keep in. I'm not saying that iconic picture of me wasn't smart, but this is me now."
She smiles, like butter wouldn't melt.
Jo Frost will tell you that she fell into nannying by happy accident. She was born in London in 1971 to a British father and a Gibraltar-raised mother, the latter succumbing to breast cancer when Jo was just 24. When she left school at 18, she decided to indulge her love of acting by taking a college theatre course, but within two years had become instead a full-time nanny. Here she excelled, and before long her reputation for dispensing smart baby sense elevated her into a freelance troubleshooter, fielding calls from desperate parents all over the world as one mother recommended her to the next, each begging for sound advice. Her eventual promotion into television came shortly after her 32nd birthday.
"I still loved what I was doing, but I knew that I had reached a level where I had to take the next step up. I saw an advert in a magazine for Supernanny, so I went for it."
Her voluminous character was perfect for the small screen. As has been demonstrated already, the woman sure can talk, while her combination of guile, babble and boundless enthusiasm rather reminds me of Geri Halliwell (or, for that matter, your average MP). She has an unerring ability to keep on-message, and so while I try to discover what effects fame has had on her private life, she repeatedly steers the conversation back to the book and the TV show, for which she craves the oxygen of publicity. There is something bluntly no-nonsense about her, too, almost overpowering. It's easy to imagine her with a whip and handcuffs.
"People think I'm terrifying but I'm really not," she insists. "I am firm, yes, definitely firm, but I also have fun, I like my champagne, perhaps a rum and Coke, a laugh with the girls, all of that. Honest."
Her escalating success, meanwhile, has brought with it inevitable flak, much of it focusing on her apparent fetish for punishment. She is, for instance, a big believer in the Naughty Step, where bad children are sent to sit and ponder their crime until an apology is forthcoming. In the short-lived Supernanny magazine that Ricochet launched last year (which Frost insists she had little to do with), the Naughty Step was a popular feature, readers sending in pictures of their own children looking miserable on them. Surely this was tantamount to public ridicule?
"Actually," she snaps, "I'm not aware of any criticism."
She is unaware that not everyone approves of her childcare methods?
"What I mean is that I don't look out for the criticism, but I do know it's out there, yes. Everybody is entitled to their opinion. All I can say is this: what I'm doing with children is good, solid common sense."
She's right. While much of her advice may well come issued in the harsh tones of a particular kind of madam, she does indeed dispense good common sense. Few people could have a problem with, for example, her extolling the virtues of a sensible diet for our children, or the importance of routine, restraint and boundaries.
Perhaps, I suggest now, the real secret of her success is that, like her bestselling counterpart Gina Ford (who also inspires a mixture of devotion and derision), she herself remains childless? After all, it's easy to administer a hardline to kids when you don't have the emotional pull that all parents are helplessly prone to, right?
"Actually no," she says. "I'm just natural with initiative, with instinct. Paediatricians have said so themselves."
Does she want to become a mother one day?
"Possibly, yes, but now my work is the priority. I'm so busy I don't even have time to meet somebody and start a relationship at the moment [she still lives at the London family home with her father], much less have kids."
It sounds like a considerable sacrifice. Is it?
"Maybe, but it's an important one. My aim is to bring about a whole worldwide equilibrium so that parents can understand the dynamics of it all as to what is, you know, unfolding as a result of their actions. I want," she concludes, now slightly confused herself but ploughing on regardless, "to promote clarity and focus. Does that make sense?"
' Jo Frost's Confident Baby Care' is published by Orion at £12.99. 'Supernanny' continues on Channel 4 at 8pm on Wednesdays