If you were asked to compile a list of candidates for TV mother of the year, odds are good you might forget to consider Julie Cooper-Nichol of "The O.C.," the Thursday Fox drama nearing the end of its second season.

After all, last season, Julie indulged in a guilt-stricken but torrid affair with one of her teen daughter Marissa's (Mischa Barton) hunky classmates (Chris Carmack). And her relentless social climbing and obsession with status helped drive away first husband Jimmy (Tate Donovan) while upping Marissa's already heavy booze intake.

But since she was introduced as a shallow, stereotypical socialite in the show's 2003 pilot episode, Julie actually has undergone something of a transformation, says actress Melinda Clarke, Julie's off-screen alter ego.

"When we first met Julie, she was there mainly to represent everything the Cohens are not," Clarke says, referring to the good-hearted clan that adopted troubled teen Ryan Atwood (Benjamin McKenzie) on the nighttime soap. "Julie spoke in this kind of a smiling Stepford manner, but underneath the smile was the subtext of 'Jimmy, I want a divorce.'

"Ultimately, she has been shown to be much more dimensional than that. There has been a real arc to the character, and as flawed and misguided as Julie is, the most important person in her life is her daughter Marissa -- and I'd like to say Kaitlin as well, but we haven't seen much of that character so perhaps that isn't quite as well-established," Clarke adds, laughing.

The actress is alluding to Julie's younger daughter, who supposedly is away at boarding school and has almost never been seen since the show's early episodes. "I like to say I have her tied up in a closet somewhere," Clarke jokes.

Still, she firmly believes Julie is genuinely trying to repair her fractured bond with the troubled Marissa, even if her clumsy attempts at a reconciliation only seem to drive the girl farther away.

"Julie's intentions are good, but her manner, the way she goes about things, is just intensely wrong," Clarke says. "She does love her daughter very much, but she doesn't know how to have a successful relationship with her -- with almost anybody, for that matter.

"I'm sure that comes from her past, and (series creator) Josh Schwartz has said to me that Julie probably has one of the most interesting and textured pasts. We've only seen a fraction of how she managed to actually get to this position of society in Newport."

Clarke is understandably eager to explore that "interesting past," which "O.C." fans recently have learned included making a porn tape during an earlier, more desperate point in Julie's life.

"What I have been told about Julie's past is actually quite a bit darker than I had expected," Clarke says. "I've always imagined that Julie had an abusive or an absent father, since her mother had to work herself to the bone at two jobs and was on welfare and facing the worst possible of situations, which is what ultimately drove Julie to do erotica.

"I actually had a very strong reaction to that story line when I read it, and it wasn't easy for me. It's just that being a mother myself, I immediately thought, 'Oh, great. Now I can't let my daughter watch this.'"

That would be Kathryn Grace, Clarke's 5-year-old daughter with husband Ernie Mirich and a frequent guest on the set of "The O.C.," although Clarke is very careful about what she does and does not allow her daughter to see.

"I don't let her watch me kissing other men, especially young men like Chris Carmack," Clarke says. "If you ask her what she thinks of her mom on TV, she'll say, 'I like her, but she's me-e-e-e-an.' She was only 3 when I started the show, so I have worked hard these past two years making sure she understands that it's not real.

"She thinks Mischa is her sister, since she plays my daughter on the show, and she actually has called 'action' and 'cut' on the set before, so I'm going to have to watch that. She's kind of bossy."

While Clarke insists that Julie looks and acts far more like a grown-up than she herself does in her off-camera life, the actress does seem to have a far clearer perspective on what motherhood means to her.

"Having a child actually has changed my life tremendously because, obviously, you have this other life that you're suddenly responsible for, 24/7," she says. "It's one of the most difficult jobs in the world, but also the most rewarding.What I do for a living is fun, whereas motherhood has given me a connection with my daughter that is deeper than I have ever experienced with any other human being. It's always growing and mind-blowing."

Clarke says she is enjoying what she describes as "the most dimensional character of my career.

"Some people say Julie is the Joan Collins of our show, but I always thought of that character as being a much more arch, obvious villain," Clarke says. "In many respects, Julie is a funny person. She definitely has a sense of humor, although it isn't always playful. If you watch the show, you'll notice times when Julie behaves kind of like a teenager herself, although she always tries to behave like an adult around Caleb," her husband.

And, she hopes, like a real mother to Marissa and Kaitlin. Of her younger TV daughter, whose extended absence has been the fodder of jokes among "O.C." fans, Clarke hints that there may be a payoff next season.

"I think next year we'll all be pleasantly surprised to get a lot more information about what's going to happen with Kaitlin," Clarke says. "And from what I understand, she might miraculously have gotten older, too, but you didn't hear that from me.

"I've heard a few other rumors, but you probably wouldn't want to quote me on those. Josh is good at keeping secrets, but I feel pretty certain by the middle of next season, the audience will find out what's going on with Kaitlin."