It’s that extraordinary day in London, the recent Monday when snow covers everything and no buses run, when schools are closed and strangers smile at each other in the street, thus acknowledging both the beauty and sudden emptiness of an unexpectedly transformed capital. Emily Blunt needs to be in Los Angeles by tomorrow evening but the news is that all flights out of town have been delayed, if not cancelled.

Resourceful, the actress has booked a 5pm seat on Eurostar and now will seek to make her onward journey via Paris. That means she cannot meet me for tea this afternoon, as had been planned. And that’s why she has invited me to come instead to her apartment this lunchtime. An out-of-the-ordinary day indeed. Actors hardly ever invite journalists into their homes, unless of course they’re being paid to. Why would they?

Not that I feel I’m invading an intensely personal space. Blunt’s first-floor flat, close to the fashionable shopping streets of Notting Hill, is high-ceilinged, open-plan and filled with the kind of large and rather formal pieces of modern furniture you might encounter in a boutique hotel. Tracy Chapman plays softly on an iPod docking station. Blinds are drawn against the pale winter light. And if these calm, clutter-free rooms suggest only occasional occupation by their owner, that’s because hers is a peripatetic life these days, much of it spent filming on location, or in LA.

It was an acidic, clever turn as PA to Meryl Streep’s fashion editor in The Devil Wears Prada that first gave her status in Hollywood. Three years on, she has a mini log jam of movies waiting to open, both big budget and indie. Collectively, they should raise her profile in the US to a Winslet or Knightley level of prominence. Coming at us first is The Young Victoria, in which she successfully humanises the least amused monarch of all.

Scripted by Julian Fellowes, directed by Jean-Marc Vallée and co-produced by a four-strong team that includes Sarah Ferguson, the Duchess of York, whose idea the project was, Victoria attempts to change our perception of the titular Queen as mournful, sour-faced and repressed by concentrating on her teenage accession and romance with Prince Albert (Rupert Friend). And though its audience will find their emotions directed firmly hither and thither by soaring strings and what, at times, is the rather educative nature of the script, there remains an energy to it that derives almost entirely from Blunt’s luminous performance. “But then she was remarkable, even as a young women,” the actress says of her character. “This diminutive thing could enliven the atmosphere in a room – or freeze it. I thought, ‘I can really do something with this.’”

Undoing the packaged spoils from her trip to a nearby upmarket deli, and transferring lamb kofka, vegetable frittata and Thai bean salad on to a platter for sharing, Blunt herself is anything but regal. “I’ll have you know I fell on my backside bringing this back for us,” she tells me, setting table places and looking around a room in which only the bare minimum of personal possessions are on view. Yes, she says, LA is a home from home these days, and is where her closest friends are. “But it’s never quite the same as London, and I’m always reminded of that when I’m travelling back. I just start to breathe easier as the plane comes into land here. It happens every time.” Even so, a willingness to travel is fortunate given that there is now a real momentum to the career of this well-balanced, well-mannered former Roehampton schoolgirl. Future stardom is seeming inevitable.

Hollywood royalty

What is perhaps most striking about Blunt on screen (a constant, this, across the wide spectrum of roles in which she has appeared to date) is how entirely natural she is. There’s nothing needy, showy or ingratiating about her. It is as if she’s always known the truth of what she says is one of the best pieces of advice about acting she has ever been given, by Alan Arkin, her co-star in Sunshine Cleaning (an independent title that premiered recently at Sundance): “A scene doesn’t have to be perfect. It just has to be real.” Such authenticity led Streep to comment that Blunt was one of the best young actresses she had ever worked with (generous, given that some critics judged the British newcomer to have stolen scenes from under Streep’s nose). Three years on, a mere reference to that compliment causes the now 25-year-old to touch her heart.

“That meant the world as she’s my hero, absolutely. There are so many things to admire about her, but foremost among them is the way in which she’s maintained her mystique. I mean, she’s the mother of four but has never broadcast that to the world. She is so private. She goes to work and then goes home: it’s two different lives. She’s created that balance for herself and has lived like that for years, despite being so celebrated for her work that it’s like there’s a whole Meryl Streep religion going on… Her being so irreverent and eye-rolling when it comes to all of that worshipful stuff is something else I love about her, of course.” It’s interesting that Blunt should cite the older woman’s ability to separate successfully her professional and personal identities as being that which she most admires, but then privacy is something of an issue for her too right now, as I will discover.

Blunt is the second of four children, born in 1983 to a QC father and an actress-turned-English-teacher mother. She grew up close to Richmond Park in leafy southwest London, and in what she describes as “a big, rowdy, loving, supportive family” to whom she remains extremely close. An older sister, now a literary agent, lives around the corner from her; a younger brother, 19, and sister, 17, “are still schooling it, poor things”. From her parents she thinks she’s inherited sensitivity and the tendency to trust others, sometimes to a fault (her mum), tempered by an ability to bounce back if let down or proved wrong (her dad). “It’s all water off a duck’s back to him and I’m also definitely a good recoverer. I’m certainly not an innately melancholic person. I think I’m a good and healthy mix of the two.”

She attracted an agent while still taking a performing arts course at Hurtwood House, which bills itself online as England’s top co-ed establishment for boarders and a stepping stone between school and university. She made her professional debut at the Edinburgh Fringe before completing her A levels, and was soon scooping up roles, including the much-praised My Summer of Love (2004), a story of across-the-class-divide teenage lesbian infatuation. What might she have done if not all of this?

“I think about that a lot, and don’t know what on earth,” Blunt reflects, spearing vegetables with a fork. “It wouldn’t have been drama school. University probably, to do languages. I was just drifting around like most teenagers, looking for a direction in which to go.”

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