Mary Steenburgen knows her performance in "Cross Creek" is, well, strange.

A lot of people, she sighs, aren't going to like it.

"For some people it works, and for other people it's probably not going to," she says in her soft Little Rock lilt. "It's not the kind of Katharine Hepburn-'African Queen'-type thing and it could have been that in a way, but to me the film is more interesting than that because the characters are more real."

Steenburgen (the "g" is soft, as in "sturgeon") portrays Marjorie Kinnan Rawlings, Pulitzer Prize-winning author of "The Yearling," who chucks her Manhattan husband and friends for a life in a remote, rundown Florida orange grove. In her cottony dresses, she taps out her stories on the front porch and stares wide-eyed at the locals who supply the budding writer with enough characters and color to eventually secure her place among American literati.

It's a frustrating performance, reticent and reserved and not at all what you might expect from the 30-year-old comedian who wowed the critics as Lynda Dummar three years ago in "Melvin and Howard" and snagged an Oscar for best supporting actress in the process.

Steenburgen is sitting at a hotel breakfast table. She is sweet and fragile looking, with a mass of soft brown curls framing a Botticelli complexion and those brown luminous pools outlined in charcoal.

She orders half a grapefruit and a pot of decaffeinated coffee.

She and British actor Malcolm McDowell ("If," "A Clockwork Orange"), who have been married three years, have two children, the youngest just 11 weeks old. "No matter how careful we seem to be, I keep getting pregnant," she laughs.

She says her self-contained performance in "Cross Creek" was not a deliberate effort to change her image from daffy dame to dramatic doyenne. "It wasn't an effort to get away from that . . ." Her voice trails off. "The thing was," she leans forward, "she's a voyeur and, uh, there are some scenes that are mine, and other scenes where I consciously hold back and let someone else have the scene. Actors aren't accustomed to doing that very much. In my opinion, it had to be that way.

"Playing a writer has always confounded actors because it's really an internal process. To try to fill up the screen with what's really in here," she says, clutching her collarbone, "to try to make that external is really difficult. You had to fill up that time, with very little to say and very little to do.

"I know it's a strange performance," she says, settling back in her seat, "but I'm proud of it. Before she was published as a writer, she was almost emotionally constipated. Nothing else worked until that worked."

Not unlike Steenburgen herself, who had to leave home to find it.

Raised in North Little Rock, Ark., she migrated to New York at the age of 19 and enrolled in Sanford Meisner's Neighborhood Playhouse. Six years later, paying the bills by waitressing and acting in an improvisational comedy troupe, Steenburgen was spotted by actor Jack Nicholson in the reception room outside Paramount's New York casting offices and sent to Hollywood for a screen test. Her first film role was in Nicholson's "Goin' South."

"The good thing was it was sudden stardom after six years of waitressing which were very important. It gave me time to grow up a little bit."

The studio wanted her to change her name, which is of Dutch origin. She refused. "I'm fond of my name. It's like an old, funny-looking friend."

Next, she appeared in "Time After Time" with Malcolm McDowell; and in 1980, "Melvin and Howard."

Suddenly, Steenburgen was hot.

"I always thought it was going to happen to me. I didn't imagine it was going to be so magical or such a big thing when it came, but I always felt confident that I would be a working actress."

After "Melvin and Howard" came "Ragtime."

"The thing is, I spent a lot of time apologizing for my success to friends. Then I woke up one day and I thought, 'This is absolutely wonderful, why am I downgrading it, hiding it under a carpet, pretending it isn't there.'

"I'm not in any danger of becoming a braggart or having my head in the clouds, so why don't I at least experience the joy of it, which I wasn't even doing."

There's a commotion in the hotel lobby and a man with disheveled white hair wearing tennis togs stops by the elevator. It's Malcolm McDowell on his way back to the room.

"There's the big mouth," Steenburgen says. "Gawd what a big mouth."

They met on the set of "Time After Time" and the love scenes continued after the shooting stopped. He was married at the time, she says, so she doesn't want to "really get into it. Although it's no big secret.

"I pretty much knew I was in trouble as soon as I saw him," she says with a smile. " 'Cause he's a very charismatic person and people either tend to fall madly in love with him or just not be able to deal with him at all."

She rolls her eyes. "I was one of the former."

She says it's easier to be married to an actor, although their careers are never on the same track.

"You can't help but compare the way your careers are going sometimes. And Malcolm and I have both experienced being the upper one in the relationship and being on the bottom rung."

Trouble started in New York several years ago when McDowell was appearing in the stage version of "Look Back in Anger" and Steenburgen was pregnant with their first child, Lilly. "It was very hard for me. I was so jealous. The problem was, we weren't talking about it. We pretended it wasn't there. Then, when I won the Academy Award a few months later, he was the one who was . . . Well, it got so bad between us, we had to talk about it and when we did, it was better. We now enjoy each other's successes when they come. It's really nice. It feels so much healthier."

Steenburgen, in her slightly daffy down-home way, says it's a good thing she became an actress because she can't do anything else.

She's joking, of course.

"No, I'm not," she wails.

She tried to write, but couldn't. She tries to cook, but can't.

"It's gotten to be sort of a joke in the family," she says.

Steenburgen's future seems secure. She is, like Diane Keaton, Jessica Lange and Debra Winger, an actress who can straddle the thin line between comedy and drama, an actress who refused to be pigeonholed when all the world wanted her to go on playing Lynda Dummar the rest of her life.

"I'll tell you something. I was reading an interview with Susan Sarandon, who's a friend of mine, and they asked her what she wanted and she said, 'To be the world's oldest working actress.' Well, I'd like to challenge her to that!"