Her first day on the Seattle set of the comedy Laggies, Keira Knightley noticed something unusual about her director, Lynn Shelton: She knew all the grips’ names.

“Most directors are like generals or dictators, because it is like an army that’s underneath them,” Knightley says. “But there was no hierarchy. Lynn didn’t just know everybody’s name, she knew their partner’s name, their kid’s name, their kid’s school. It was so chill. You felt like you could make a mistake and it would be OK.”

Like many of her characters, Shelton has a breezy, natural conversational style and a quick wit. Long-limbed with bright blue eyes and a wide smile, she could work in front of the camera and has, playing small roles in her own films and those of her friends.

But her den-mother directing style was cultivated through persistence and an impressive body of work, including five previous independent features, most notably the unconventional comedies Humpday and Your Sister’s Sister, as well as on episodes of Mad Men, New Girl, The Mindy Project and other TV shows

“I self-generated my work, and I never went around asking permission to make it,” Shelton says over coffee. “The main reason women make inroads in independent film is that no one has to say, ‘I pick you.’ I’m not pounding on anybody’s door. I’m just making my own way. You can buy a camera for $1,500 [Dh5,509]. It’s insane how easy it is to make a movie. You can make mistakes and throw it under the rug and keep going. You’re not dependent on other people allowing you to do it.”

Laggies, in theatres from January 1 with Knightley as a drifting 28-year-old who passes her days as a sign twirler for her father’s accounting company, is Shelton’s most mainstream film to date and her highest budget, at a number she’ll disclose only as “several million dollars.”

What Laggies is not, however, is a studio movie — it’s being released by A24, the distribution company behind Spring Breakers and The Bling Ring. Like many of the busiest female directors in Hollywood, Shelton, 49, works steadily in the realms of independent film and TV but has never made a studio film.

And until Laggies she’d never made a feature she didn’t write herself. Shelton latched onto novelist Andrea Seigel’s script, she says, because of its realistic portrait of a young woman doing what young men have done on the big screen for decades — floundering.

Seigel wrote the script after seeing a particularly exuberant sign twirler on the street and wondering about the young woman’s interior life. In the film, Knightley’s Megan is standing still developmentally, as her friends move on with marriages, careers and adult responsibilities. Stunned by a proposal from her longtime boyfriend (Mark Webber), she lies to him about going on a retreat, escaping instead to stay at the home of a teenager she meets in a parking lot (Chloe Grace Moretz) and the girl’s dubious father (Sam Rockwell).

“The female protagonist was allowed to be fully flawed and fumbling her way toward her own identity and be really human,” Shelton says. “It’s a new thing that women are being given permission to inhabit that kind of territory, whereas men, the first one I can remember is The Graduate.”

Empathically funny portraits of searching young women are popping up in culture, as films like Gillian Robespierre’s Obvious Child, about a comedian’s unplanned pregnancy, and TV shows like HBO’s Girls and Comedy Central’s Broad City feature twentysomething women grappling with the often-messy transition to adulthood.

“Female protagonists have had to be what Hollywood thinks is likable, but they’re scared to let women make bad choices,” Shelton says. “They want to smooth off all those rough edges. That comes from a societal desire to have women be idealised, and so you end up with these cardboard cutout facsimiles of what a real woman is. I do feel like there’s a new trend, though, an opening up. Maybe the studios will allow more unconventional characters and relationships to unfold.”

Shelton grew up in Seattle, where she lives today with her husband, onetime MTV VJ Kevin Seal, and their teenage son. After getting a theatre degree from the University of Washington, she took a stab at acting in New York and earned a master’s in photography from the School of Visual Arts there. She was working as a film editor when she directed her first feature, We Go Way Back, about a 23-year-old actress in dialogue with her 13-year-old self, which arrived in theatres with a whisper in 2006.

Her 2009 comedy Humpday, a micro-budgeted bromance about two heterosexual male friends dared into entering an amateur porn contest together, exploded out of the Sundance Film Festival, earning Shelton an agent and manager; in 2012, Your Sister’s Sister, in which Shelton re-cast Humpday’s Mark Duplass in a relationship triangle with sisters played by Emily Blunt and Rosemarie DeWitt, found a still wider audience, thanks in part to VOD.

Shelton’s first TV job was a 2010 episode of Mad Men. Though she had directed three films by then, she had never worked in Los Angeles, with a union crew, or on a sound stage.

Mad Men was at first very daunting, and then I quickly came to realise that directing is directing is directing,” Shelton says. “The scale of the production is that the cinematographer either has one person to help him or an army of people. Once I was finished with that experience I was like, ‘Oh, I could walk on the set of a studio movie now.’”

Since Humpday, Shelton says, her representatives had been looking for a project that would allow her to work with a bigger budget and larger palette.

“They’ve sent me a continuous stream of scripts to see if something sparks,” Shelton says. “At a certain point I was like, maybe we should just stop with sending me scripts. They were beautifully written, but it’s so, so rare that there’s any kind of overlap with me or an affinity for the writer’s voice.”

Laggies was the first script where she felt a connection to another writer’s work. It was also the first time she relied on any kind of traditional financing, having made her previous movies with money from grants and house parties.

“I made five films that I literally had nobody on the producer/investor end giving me notes or wringing their hands, so I got really spoiled,” Shelton says. “Laggies was the first time I had a dialogue with those folks and it went really well. I never felt bullied into making compromising choices, but I wouldn’t want it to get any more involved. I wouldn’t want to make a film I’d be afraid to put my name on. It feels like the more millions involved the more likely it is that that’s going to happen unless you have some kind of protection or buffer.”

By buffer, Shelton says, she means the kind of power producer who has enabled Lena Dunham to make Girls her own, Judd Apatow.

Laggies has earned mostly positive reviews — while critics have praised the performances, particularly Knightley’s corset-free physical comedy, some have lamented that it lacks the shaggy appeal of Shelton’s earlier films.

Shelton is currently nursing three feature scripts at different budget levels and shooting Fresh Off the Boat, a sitcom about a Taiwanese family that moves to America in the 1990s that ABC will premiere in 2015.

“What would the $200-million Lynn Shelton movie be?” Shelton asks. “I don’t know. I’ll think of one and make it in my mind.”