There’s something very unexpected about meeting Liv Tyler. It’s not that she’s even more beautiful in real life than she appears in pictures (which she is, by the way; disarmingly so). It’s not that she’s toweringly tall — she’s 5ft 10in and that’s before heels. It’s not that, as an established member of Hollywood royalty, she’s relaxed, well mannered and interested in the people around her — our meeting starts with her asking my PR companion how her breast-feeding is going, and she’s sad to learn it isn’t going anywhere. “Oh, but it only hurts for a couple of weeks and then it’s so great!” she cajoles, before turning to me, diet Coke in hand, and asking: “Shall we go next door and start gabbing?” It’s not even her remarkably glossy mane of dark hair or that not a single wrinkle is perceptible on her 31-year-old face (she’ll be 32 in July, she tells me). No, it’s none of that stuff. It’s that this woman, so often considered to be the voluptuous, homely girl-next-door, has developed some serious phwoar! factor.

There is no sign of squidginess on the body sitting in front of me, one that has, in the past, yo-yoed from slim(ish) to decidedly curvy. It’s quite the opposite now: she is so seriously toned that you can clearly make out delineated quadriceps beneath her black Wolford leggings. She seems more in control — even of her sexuality, which used to spill out like its own force field, just like those soap suds she wallowed in while washing the car in that famous scene from the movie One Night at McCool’s.

In fact, the girl who was unaware for most of her childhood that her real father was the rock god Steven Tyler, and who landed her first lead in a movie aged just 16, appears to have done a bit of a Gwyneth and transformed herself from “normal” to well-honed totty. Of course, for Gwyneth it was about making a point of emerging from a self-imposed hiatus as an (almost) stay-at-home mother. For Tyler, it’s a sadder story: she is emerging from the rubble of divorce from the British musician Royston Langdon, the father of her four-year-old son. Clearly, it has made her toughen up. After all, only a few months ago she admitted to being devastated when he moved out of the family home, and that it was so hard to be in her New York home without him that she had to move to California. “The hardest part is when they leave,” she said. “It also brings up a lot of issues — you might feel like a failure, or like there is something wrong with you. You can’t run away from yourself — you have to just deal with it.”

Deal with it she has. There was last year’s blockbuster movie The Incredible Hulk, following on from starring roles in The Lord of the Rings trilogy. There’s a new romcom, The Romantics, in the works, and she’s just signed on for another two years as spokesperson for Givenchy, having already held the role for six. She’s also streamlining things. “I go through phases,” she says. “But, especially when I got married and I had Milo, I wanted to nest and have a family in a way that I’d always dreamt of doing. And I love to cook — I’m such a Cancer in that way. I like to be at home and then when I work I like to work really hard.”

Now, though, she also works out hard. To escape her heartache, she threw herself into a fitness regime. She reportedly trains with David Kirsch in New York, a fitness guru who has worked with the likes of Heidi Klum. Recent pictures of Tyler and Kirsch kissing in a parking lot sparked rumours of a post-divorce love affair, evidence of our heightened fascination with the love life of Hollywood’s sexiest new singleton.

She’s also learnt that exercise should be enjoyable. “I recently got a hula hoop and I’ve been living in LA [she has said it is hard to be in her New York home without her ex]. I put my favourite song on and stand outside and hula hoop in every weird direction until the song’s over and I’m all out of breath. It’s really fun.”

She has also learnt to be at one with herself. “All you can do really is try your best and accept yourself. I’ll always have a more round stomach, but thank God I have thin ankles.”

There are dichotomies with Tyler, however. When she talks, her voice is still quiet and breathy — more like a child than a sex kitten. Despite this, she seems to be fiercely independent. “I want to be able to decide what I’m doing with my life.” She says she “really enjoys dressing up”, but admits being addicted to her sloppy tracksuit bottoms. “The moment I get home I take everything off and put my sweats on or my pyjamas — I like to be comfortable.”

She clearly loves clothes, but says she has “stopped buying fashion magazines. I mean, it’s such fun, but I don’t want to be influenced by everyone else about what’s cool or not cool; I want to be who I want to be”. So, for all the glamour, she’s a grunge girl at heart. No wonder she admits: “I still have my original pair of Converse trainers from when I was a teenager somewhere in my closet.” She also owns up to driving barefoot. “I can’t drive in heels, so I always take my shoes off. Gwyneth is the best driver in heels ever! I’ve seen her, and I have no idea how she does it.”

It’s also clear that it’s her role as a mother that influences her most, and she wants to be as hands-on as possible — which means the usual disruptions. “Milo [who calls her his princess] wakes up every morning at 5.30 or 6 — ping! — and so the hardest thing is the lack of sleep. I try and go to bed before 10 or 11pm, but it’s so hard. If I don’t get more than six hours of sleep for a few days in a row I start to really lose it and just feel so panicked and stressed. When people ask me, ‘What is the first thing you do in the morning? What’s your routine?’ I say, ‘Er, I get up. I make breakfast,’” she laughs breathily. “‘I beg Milo to try and snooze for 30 more minutes!’ Of course when they’re up, they’re up.”

She has added pressures in the motherhood arena; for her, the yummy-mummy contest at the school gate is on an altogether grander scale. “The hardest thing is taking him to school, as sometimes I’ll literally just throw my coat on over my nightgown, but the paparazzi wait almost every day outside his school. It’s so hard because I don’t want to think about what I’m wearing when I’m taking him to school. I want to get him to school safely, then do whatever I have to do.”

Still, that independent streak kicks in: not for her that dressing-up-for-the-press malarkey. “I’m an on-off celebrity,” she says. “I couldn’t live like that all the time. I don’t know how people do it. Honestly, I like a great trench coat and to throw it on over something; I don’t want to be obsessing all the time about my outfit. I love being a mother and a normal mother as much as I can, doing basic things. And I love my job and being spontaneous in life, and if you’re trotting around in heels the whole time, you can’t really do that.” Just as well she’s held on to those Converse trainers, then. Right now nothing is going to slow Tyler down.

LIV'S BEAUTY FAVOURITES

Givenchy Phenomen’Eyes “It’s genius. Why didn’t anybody think of it before?” £18.11

Vernis Please! nail varnish in poetique lily Great on pale skin. £11.75

Rouge Interdit lipstick in poetique iris Not red and not orange, just nice. £17.62

Skin Targeters Black for Light mask It brightens your skin. £52

Prismissime Eyes in poetique browns “You can choose the colours you want.” £32.79

Beauty icons Women with something sympathetic in their eyes

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