And she's not even that tall. She just looks it.

She certainly looked it the night before we met (I mean met properly, having discounted the idea that you can 'meet' someone by looking at them naked on a stage for 17 seconds): she was all stilettos and susurration as she sashayed into the spotlight in Los Angeles's Wilshire Theatre, three minutes in, as Mrs Robinson in The Graduate, and promptly began to steal the show; by half-time it was in the bag marked 'swag' and by the curtain she was scot-free away with it.

Not that this was a particularly difficult production to rob blind. Excuses were being made outside, in smoking pariahs' corner, for the male lead. How could anyone compete with Dustin Hoffman? But by the same token you could argue no one should hope to reprise Anne Bancroft, and Miss Hall had just done so and then some.

'How do we think Jerry's doing?' asked a couple of LA matrons, chaining away as the late Pacific light painted Wilshire Boulevard sunburn-pink. 'Put it this way, honey; she's not just the reason we're here: she's the only reason we're going back in for the second half.'

But, still. Actress, scene-stealer, model, wife, model wife (if you go in for the virtues of forgiveness and stoic family-building), icon to some of our admittedly more confused feminists, party girl, long-haul divorcee, that worrying word 'survivor' which people can lazily drop in without wondering precisely how hard it can be to survive on nothing but looks and talent and a £7 million settlement - but, thank goodness, not that tall. I know because I made her stand right beside me and I wasn't hideously embarrassed. She was in bare feet, yes, but I wasn't actually standing on the table, which I count as something of a triumph. Tall, you see, is one of the words that gets wheeled out so often about Jerry: tall, and Texan, and Mick's ex.

What they don't tend to mention is a rather quick, wry brain, and a determination to be known as that least sexy of things, a good mother. She's had it, she says now, with most of the glamour. 'All the celebs? All the parties? No, I don't miss them for a second. A lot of those people are not living in the moment.'

There is also, she hints towards the end, a faint residual bitterness at the number of apparently mutual celebrity 'friends' who, after the divorce, let her drop faster than Mrs Robinson sheds her peignoir , but she doesn't want to get into specifics. What she is happy to go into details about is now, and the future, and, perhaps surprisingly, Mick.

'We had fabulous fun,' she says of the world's most priapic pensioner. 'But I couldn't stay, I just couldn't stay. There was always another woman, always another drama. It was just too tiring, too much hard work.

'I was with him for 25 years. I don't know more about anyone else. And yet it would always somehow turn into a Strindberg play, I'm not quite sure why. Thing is, he's still my best friend, we chat by phone every day, and he seems pretty proud of and impressed by me. We have wonderful children - bizarrely, they don't do drugs, they're not in any way self-destructive. Mick has 50 per cent custody, and we never fight over them. The divorce itself - well, yes, there were fights, but to be fair it was his lawyers who told him he should fight it that way. He felt bad about it afterwards.'

Some of this could, from a different mouth, be written off as false bonhomie, a Hollywood desire to smile, smile through heartache, especially that particular ego-ache women must feel when being left for younger models. But there doesn't, in truth, seem much that desperate about Jerry Hall, if there ever was: she is not kicking particularly hard against time's march.

'I've spent years in a business where everything has to do with how you look. And after a while, at a certain stage, you either move on or you try fanatically to keep it going. It's a mistake to go and have plastic surgery. I haven't. And I don't want to.

'I've been extremely lucky in that I've been a very successful model for a long time. So now I'm an actress, and a mother. I'm a theatre rat, which I always wanted to be - I've wanted to act since I was 14 - and I never get bored, ever, and I have four beautiful children. I am, in fact, so darn lucky.'

What, though, of the looks: would she have had anything like the same life without them? 'Well, actually, I know people who you wouldn't think are particularly beautiful but who are incredibly happy in their own skins...' and she peters out, a little, too smart to want to bullshit her way much further down this route. 'OK, then, if I hadn't had the looks, I would have... I probably would have gone into chemistry. I would have liked that.'

So the world lost a leggy chemist, and gained for many years a rather professional model, and now something she might hate to be described as but almost definitely is, which is a Personality. The BBC certainly reckoned so, having signed her a while back for a three-part series entitled Jerry Hall's Gurus in which she goes, allegedly, in search of spiritual enlightenment.

'They came to me and wanted me to do a programme. They wanted me to do a travel programme, for instance. Actually I wanted to do something which interested me: and I went and lived in India, for a while - it was valuable, and, yes, I am interested in spirituality. I think it's part of human nature to seek that out, to try to want a spiritual life to help you be a better person.'

Maybe it's just California getting to me here but I find myself starting to nod, sagely, as she leans forward, smoking, charming and earnest. And then I remember the programme.

Jerry may not have wanted to make a travel programme but in many ways that seems to be just what the BBC wanted of her. And why not, you could ask: she's got looks, presence, a surprisingly sharp and unbubbly sense of humour, and looks like she's enjoying herself. Many viewers will want to be her as she suffers spas and facials and five-star foreign hotels and interviews people such as, er, Mick Jagger.

But a deep and questing search for spiritual enlightenment it is not - not unless your chosen way of reaching a higher plane is through gritted teeth. The first programme spends time simply rehashing the old story of alleged 'improprieties' perpetrated against Mia Farrow by the mendacious old Maharishi, a man who told reporters back in 1968 that his brand of spiritual peace 'could only truly be appreciated by men of the world with rewarding activities and high income' and thus famously, and quite accountably, wooed the Beatles successfully. Jerry, for all the canny-eyed wit she honestly seems to sport in real life, somehow finds herself on screen spouting insights such as: 'I think this river has something very magical about it. Something very spiritual.' The river is the Ganges. 'So much energy and prayer been done here. Like when you go to a temple, you feel that, so much spiritual energy in the place.' She doesn't actually go in because there's too much pollution.

She talks up Kaballah, an 'offshoot of the Hebrew faith', which would seem to say essentially that the way to spiritual nirvana is to become filthy rich: an approach which has wooed Madonna and Guy: Jerry was into it for a bit but dropped it when it began interfering with her schedule.

She talks up, too, one Deepak Chopra ('How do you keep your ego down?' he answers her at one point. 'By reminding yourself that when you're feeling self-important, you're actually feeling sorry for yourself'), arguing that in some ways it is a good thing that the guru, now living in California, has successfully 'managed to repackage thousands of years of eastern philosophy for a Western audience'.

There may be many viewers out there who will love to see Jerry happy in the sun, flinging her glinting hair around and looking insanely relaxed after too many years of sympathy for the devil, and telling them 'I've had quite a lot of heartbreak and I felt the the whole experience was... healing for me', and watching her chat to her neighbours and best friends - Anjelica Houston, Richard E. Grant and the like, about, hey, how they've survived. I tried to watch the second programme, on spiritual fashions but it was more of the same. My brain was shuddering and I suddenly remembered half way through that I wasn't, in fact, Princess Diana. Goodness but she would have loved it: she would have sat, rapt, through a thousand re-runs; the entire Palace staff could have been involved in screaming Bacchanalian orgies in the next parlour and she wouldn't have noticed.

And then, in the third programme, just as you're thinking how ill-served Jerry has been by the series - her lazy Texan drawl, quite charming in real life as she leans towards you, can sound merely lazy when it's spouting voiceover gibberish over pictures of Indian men in big orange nappies - she suddenly redeems herself. The quest gets a little more serious as she tries, honestly and in a much more subdued fashion, to find a way to help her sister Terry, who has just come through a serious breast cancer scare and been left with heart problems because of all the chemotherapy. There is nothing false, either in the series or when she talks to me directly about the depth to which this has affected her, nor her need to try to help; she has willingly talked to mad old Indians and wannabe angels and been blessed by a shamanic bear dance. It's all rubbish, of course, but it's rubbish with the best intentions.

And then one day, far enough away from shops, celebrities and bearded charlatans, on a hillside retreat high in northern California, she underwent an odd little massage, and suddenly, unwittingly, in front of the cameras, the dam broke and the tears came. Tears for her pent-up emotion: for her father, who whipped his children, and for her mother, with whom she still feels angry for not protecting them.

'I have changed, in that I'm calmer,' she says now. 'I never had a script, never had a plan, always felt I was just making things up as I went along... but now I am so happy, as I say, with things such as my studying - I'm doing a second degree, now; Mick says he's so proud of me! - and my acting. I would like I suppose to do more comedy - even if it's cruel, because truth is cruel, life is cruel, honesty is cruel. And away from that, of course, I have my children.'

When, I wonder, is she happiest, these days? 'I have a horse which I ride in Richmond Park, and there are times when Georgia May [her 11-year-old daughter] will come along, and that's getting pretty close to happiness.'

As for a new love, she sighs when I ask about the possibility. 'I've been in love I suppose a couple of times. I did love Mick. I don't go out on blind dates. I've told all my friends - do not try to set me up with anybody. But I don't want to fret about it.'

And then, for all her protests about the good times with Mick, an interesting thing happens towards the end of our conversation, while talking in this way about love, to which possibility she says she is still open: I make a throw-away comment about it being nice to be a couple again, and her answer speaks volumes.

'A couple? Well, actually, that's never happened to me. That would be... that would be nice.'

· The three-part series Jerry Hall's Gurus begins on Sunday 23 November, 8pm on BBC Three

Hall of fame

1956 Born in Gonzalez, Texas, one of five daughters. Difficult family life - her father was an abusive alcoholic.

1970 At 16 left home to pursue modelling career in Paris.

1975 While dating Roxy Music's Bryan Ferry, posed on the band's Siren album cover.

1979 Left Ferry for Mick Jagger.

1984 Elizabeth Scarlett born, followed a year later by James.

1989 Appeared in the Batman movie.

1990 Married Jagger at a Hindu ceremony in Bali.

1992 Georgia May born.

1997 Gabriel Luke born.

1999 Jagger marriage annulled.

2000 Rave reviews for The Graduate.

2002 Dated financier Tim Attias. Says Mick is still her 'best friend'.