With two young children and a career to keep going Diane Keaton is usually up at 5 every morning in her comfy Spanish-style home in Los Angeles. “That’s the time I have for myself,” she says. “Once I have my coffee, it’s the best moment of my life.” So on Jan. 27 she’d been sipping a cup and noodling around on the computer for half an hour when friend Carolyn Barber, her assistant on the blockbuster comedy Something’s Gotta Give, called with news that she’d just been nominated for a Best Actress Oscar—just two days after taking home a Golden Globe. “Of course I was thrilled,” says Keaton.

So are audiences. Over the past quarter century or so, the 58-year-old actress has been aging—without help from plastic surgery—from Woody Allen’s gorgeous, goofy muse to middle-aged wives and mothers in two Father of the Bride movies and The First Wives Club. Something’s Gotta Give, about the romance between two glamorous people eligible for AARP membership, is a consciousness-raising return to the spotlight for the actress, who in recent years has been drifting away from performing and into directing and producing. “I was moving toward maybe acting once a year in a cable movie,” she says. Well, to quote Annie Hall: “La-de-da.” Something’s Gotta Give has brought her back, and reminded audiences of Keaton’s inimitably breezy style. Jack Nicholson, her costar in the film, says he was surprised at her knack for seduction: “Every once in a while,” he says, “warming up for the love scenes, she’d say, ‘I love you,’ and, man, I’ll tell you, I believed it. I didn’t know whether I was going to be engaged to her at dinner or what.”

In Something’s Gotta Give, starring Keaton as an accomplished divorced playwright to Nicholson’s world-famous ladykiller, she even dared to do her first ever full nude scene. “I slapped the makeup on and went out there,” says Keaton, who turns the brief bit into a minor masterpiece of physical comedy. “She has a great figure, as the world now knows,” says the film’s writer-director, Nancy Meyers, a longtime friend who wrote the role with Keaton in mind. “She looks fantastic.” Yet Keaton doesn’t claim to have any special regimen (“I do no exercise. None. I’m thin because I’m anxious!”) or beauty secrets (“I wash my face, put on some cream”). She loathes the idea of plastic surgery, “but you never know. Every time I say I’m not doing something I do it. I was never going to have premarital sex when I was 15…. Well, forget it. In theory I think it’s best, probably, to try and be the best authentic person you can be.”

And what star has more authenticity? Time hasn’t taken the fizz out of Keaton’s oddball charm—coltish figure, sad eyes, dazzling smile, strange clothes—but the never-married mother of two adopted children, daughter Dexter, 8, and son Duke, 3, is in private much more grounded than her famously twittery persona, which was on full display at the Golden Globes. That night she called herself “a rediscovered eccentric,” but “Diane is not in the least bit flaky or flighty,” says Meyers. “People confuse individuality with flighty. Flaky would be the last word in the world you’d use to describe Diane.” Nicholson sums her up in two words: “Idiosyncratically brilliant.”

Consider her range of interests: She’s also a photographer, movie producer (Elephant), director of films (Unstrung Heroes) and TV episodes (Twin Peaks). She’s an architecture buff and home renovator: She did such an expert job fixing up a 1920s house by famed LA architect Wallace Neff that Madonna bought it for $6.5 million. “She’s involved in the world,” says Amanda Peet, who plays her daughter in Something’s Gotta Give. On the set, “she would have, like, eight papers under her arm, The New York Times first and foremost. She would get enraged about a headline and shout, ‘Get this!’ ”

Keaton, an L.A. native and the oldest of four siblings, credits her success—in everything—not to brains but diligence. She learned that value from her father, Jack Hall, a civil engineer who died of a brain tumor in 1990. “My dad was slow,” she says. “He always said to me, ‘Diane, I’m slow, but I’m going to keep trying.’ I am my dad’s daughter in that regard.” Her mother, Dorothy Hall, seems to have planted the talent: “Secretly in her heart of hearts she probably wanted to be an entertainer of some kind,” says Keaton. “She sang. She played the piano. She was beautiful. She was my advocate.”

Now it’s her turn to raise children. “It’s just about the most completely humbling experience I’ve ever had. You try hard, but of course you always make mistakes. Being a parent reminds me that I’m not special.” Then again, “when you see her drop her kids off at school and she’s wearing a bowler hat, gloves, boots that come up to her kneecaps and a poodle skirt…I find that interesting,” says her friend, actress Sarah Paulson, laughing. When her kids visited the Something’s Gotta Give set, recalls Meyers, “Diane would drive Duke around on a golf cart. I’d see them at lunch going’ Wheee!’ ”

Her love life is apparently much quieter. (“The fact that my body functions is what I’m really thrilled with now,” she told the Associated Press.) Once she made headlines with high-profile romances that included Allen (who directed her in seven movies), Al Pacino (her costar in the Godfather trilogy) and Warren Beatty (her director and costar in Reds, for which she earned the second of her four Best Actress nominations). “To be transported [by love] is fabulous,” she says. But—when again? “Next question.” And she laughs at the idea of ever dating a younger man, as she does in Gotta Give, in which Nicholson’s unexpected rival is a doctor played by Keanu Reeves. “It’s not an issue. It’s not going to happen.”

And the Oscar? She won’t know until Feb. 29. Until then, she has her routine: “I’ve got to pick up the kids and run around like a chicken with its head cut off. I collapse at 9 p.m. I’m like a farmer woman.” A farmer in boots. And a bowler hat. And gloves.

Courtesy of People