The first thing Lisa Cholodenko learned in film school was simple: “Write what you know.” The lesson has served her well. After winning the Sundance Film Festival’s Waldo Salt Award for outstanding screenwriting with her feature-length debut, the 1998 romantic drama High Art, she earned near-unanimous accolades at this year’s festival with the poignant family comedy The Kids Are All Right.

In Kids – a title inspired, somewhat whimsically, by a 1979 documentary about The Who – Julianne Moore and Annette Bening play Jules and Nic, a same-sex married couple whose teenage children, both products of artificial insemination, track down their birth father. For Cholodenko, who attended San Francisco State as an undergraduate before moving on New York’s Columbia University for film school, it’s a story drawn in part from her own experiences as a materfamilias.

“The moms are uptight about the children [meeting their biological father],” says Cholodenko, 46, who has a four-year-old son – also by way of an anonymous sperm donor – with longtime partner Wendy Colvoin. “They’re nervous about it because the oldest child is about to leave [for college], and they’re going through the empty-nest thing, trying to hold on to their family unit.

“We needed that tension. They had to be resistant – open, on some level, but definitely resistant to the kids meeting the donor. In my family, I don’t feel that way at all. My partner and I feel like that’s something we’ll be open with our kid about when the time comes, and we’ll help him explore it, if the donor is available to meet him.”

Not wanting to embark on her latest creative journey alone – she describes solo projects High Art and her 2002 follow-up, Laurel Canyon, as fulfilling but lonely – Cholodenko wrote Kids with Simon Blumberg (Keeping the Faith), himself a former sperm donor. Together, they produced a brutally honest screenplay that struck a chord with Bening, a fellow San Francisco State alumna who began her career with the city’s American Conservatory Theatre.

“I like to think that we’re all motivated by our intense love for our kids,” says Bening, 52, a mother of four with husband Warren Beatty. “I try to bring that to what I’m doing when I’m playing a mom. Not all the mothers I’ve played make good moms, but Nic is very practical. She’s very involved, very devoted to her children, and is getting ready to let one of them go to college.

“We’re coming into a time when the offspring of all this technology, for lack of a better word, are coming into the conversation. When it comes to adoption, in vitro fertilization and sperm donors, I’m no expert, but I think the movie is trying to talk about these subjects in a contemporary way. And I loved the story when I read it – it’s so thoughtful and beautifully written. Other than the fact that the parents are gay, it’s a classic family story.”

Bening says the best directors she’s worked with, like Cholodenko, are naturally receptive, content to let their actors work rather than constantly interrupting them with critiques. Unlike Nic, whom the director describes as one of her on-screen alter egos – Jules, a free spirit, is the other – she’s no control freak. But her reticence could never be confused with a lack of vision.

“Lisa worked on this script for four years,” Bening says. “There were lots of drafts, lots of permutations of relationships and things that happened that she eventually cut out of the story or chose to heighten. That process of sifting, weeding things out and finding that tiny bit of dialogue that makes a scene work, it’s extremely arduous.

“She went through that. She’s very careful and determined. She sat there and watched us, knowing that she would eventually find exactly what she wanted, but when she spoke, which she didn’t do all that often, it really meant something.”

Now living in Los Angeles, Cholodenko admits that writing Kids with the New York-based Blumberg was sometimes a challenge – neither was being paid for the work – but believes their cross-country tug of war, and the unenviable commute it necessitated, resulted in a leaner, more authentic story.

Although she doesn’t plan to make her next, whatever it may be, a long-distance collaboration, Cholodenko still draws inspiration from her friends back east – Blumberg, of course, but also One Flew Over the Cuckoo’s Nest director Milos Forman, under whom she studied at Columbia, and onetime professor James Schamus, whose studio, Focus Features, elected to distribute Kids.

Yet Cholodenko remains influenced also by her time in the Bay Area. It was there, as a young adult, that she first seriously contemplated marriage and motherhood. In the process, the seeds were planted that came to fruition in Kids, perhaps her most personal story to date.

“Moving to San Francisco when I was 18, emerging here and coming out has certainly informed my worldview,” she says. “It was here that I started thinking about gay families. I left the city when I was in my mid-20s, but I already knew people who were starting their own families and planning to have children. That was when I began to consider the idea myself.”