Meet EmmaThere aren’t many clues to tell you that you’re standing outside the home of one of Britain’s most exalted film actresses. There’s the pretty rose, a touch of pink against the gray, in the front garden and a climbing hydrangea that gives the house an air of secrecy. But otherwise it’s just an ordinary semidetached house in an ordinary street in an ordinary suburb of London.It would be nice to write "And then you see her…" But the first moments with this actress don’t really work that way. Because when Emma Thompson, actress, writer, film star, comes to the door, her hair is scraped back, her body buried somewhere deep in a voluminous fleece top and baggy sweatpants. She greets you as if you’re an old friend, and when she drags you into the kitchen, she’s all no-nonsense movement — hurling the groceries into the fridge while telling earthy anecdotes and yanking up the fleece top to show the hairs on her navel to discuss the merits of feminine plucking. It’s only when you sit down at the kitchen table, across from those clear-water blue eyes, that slightly lopsided, surprisingly elfin face, that it strikes you she might actually be working hard to put you at ease. Because Emma Thompson may want to appear ordinary, to be ordinary, and she may still live on the street where she grew up, but she is, at the same time, extraordinary indeed. Emma Thompson is the accidental movie star. The quintessentially unactressy actress. A Cambridge graduate with leanings toward comedy and writing, she seems to have become what she is almost inadvertently. She has two Oscars cluttering up her bathroom — best actress for Howards End, best adapted screenplay for Sense and Sensibility — and that each was granted to a different aspect of her career is appropriate. You get the impression she does only what truly interests her. As the novelist Nick Hornby, with whom she’s currently working on a screenplay, says: "She’s not concerned with being a package. There’s no Emma Thompson franchise." She’ll do Hollywood (Primary Colors, Junior) or low-budget British comedy (Maybe Baby, by "my good mate" Ben Elton), she’ll play a housekeeper (Remains of the Day) or a lawyer (In the Name of the Father), an angel or a homeless person (she appeared as both in HBO’s Angels in America); the only unifying factor in Thompson’s roles is that, at the age of 46, her presence — most notably as the betrayed wife in Love Actually — is guaranteed to give a film a quality or depth, a brilliantly modulated expression of emotion.What She’s Doing NowIn her latest project, Nanny McPhee, she stars as Nanny, and Colin Firth plays the father. Thompson adapted the screenplay from Christianna Brand’s Nurse Matilda books (popular in England in the 1960s) about the naughty, naughty Brown children. "Nanny has taken up nine years of my life. It was terribly hard — but I’m most proud of it. I love it the most of anything I’ve done," she says. The film went to number one in the UK in its third weekend, which amazed her — "I normally make art-house films, so you don’t expect that" — but, typically, she takes even more satisfaction in the response of her local butcher. "Barry, off whom I buy the Sunday roast, said ‘What a good film!’ I was so pleased with that," she says. "You know, he’s 40; he doesn’t have kids. I get even more pleasure from that than from the big numbers." In Nanny, Thompson stars as the "tremendously ugly and rather mysterious" main character, and although she has been playing homely spinsters since she was a slip of a girl, she has never looked nearly this hideous before. She gleefully reports showing the trailer to Hornby: "He looked at it and said, ‘You are not going to be in any romantic comedy of mine. Ever.’" Thompson bangs the table in silent laughter. Then stops. "God," she drawls in mock despair. But she has never seemed to care how she looks on-screen — or off, for that matter.