Filmmaker Lynn Shelton didn’t direct her first film until after she’d turned 40, but she’s been plenty active since her 2006 debut, “We Go Way Back.” In addition to helming episodes of television shows like “Mad Men” and “New Girl,” she’s directed six films. Her latest, “Laggies,” comes out in wide release this week after a successful showing at the 2014 Sundance Film Festival. “Laggies” follows Meg (Keira Knightley), a woman in her 20s who runs away when her boyfriend (Mark Webber) proposes at her friend’s (Ellie Kemper) wedding. She ends up bunking with a high schooler (Chloe Grace Moretz) and her single father (Sam Rockwell) as she tries to figure out what to do with her life. The film made sense for Shelton, who said she knows a thing or two about “long, circuitous” routes leading to her calling in life.

This is the first film that you’ve directed that you weren’t also the screenwriter on. What was it about the script or the story that drew you in?

It felt, when I read it, like a movie I could’ve written. I felt like Andrea (Siegel, “Laggies” screenwriter), and I have a lot of the same kinds of concerns in terms of just wanting to represent people who feel real on screen. Specifically in terms of the actual content, it was just so nice to see a female protagonist explore her story that I’ve seen men explore a lot on screen. Starting back with “The Graduate,” this kind of quarter-life crisis. (The protagonist) is this very flawed human being who makes mistakes and who’s really stumbling her way toward trying finding her way in the world. I feel like, a lot of times, women get relegated to roles where they’re expected to have their act together, and they’re the mature one waiting around for the boyfriend or the husband. We just need more flawed, real human woman who are exploring this kind of territory, so that was a real draw as well.

You don’t see a lot of movies with a female protagonist aimed at this specific age group. What did you find interesting about Meg’s character and this idea of a kind of post-college floating for her?

Yeah, well I think “Laggies” is almost a little bit of a mislead in that I think it kind of implies a failure of some kind. It’s really about somebody who comes to this realization that she really needs to take her own life into her own hands and go ahead and embrace the fact that she’s marching to the beat of a different drummer. She really is going her own way, and there’s absolutely nothing wrong with that. I deeply, personally connect with that idea, because when I started directing feature films and then television and became a real narrative director, I felt like, my God, this is what I always meant to do. But I didn’t do it until I was in my 40s, so I had this very long, circuitous route getting to finally land where I ended up landing. And even now I feel like on paper it looks like I have a pretty conventional life. I have a mortgage and a husband of many years and a kid, and yet I’ve been able to write my own script for how that actually works. My husband is the primary caregiver of our kid, and I lead this life of an artist. And I live in Seattle, when everybody’s telling me, “You should live in L.A. or New York.” So that idea of writing your own script and going your own way is really important way.

You’ve got an amazing cast in this movie. I think you’re the first director to ever make me not like Ellie Kemper’s character in a movie, which is a skill unto itself.

And she is literally the sweetest, tender-hearted woman. Just the kindest person I’ve ever met in my life, so it was very funny to see her take this very bitchy role in hand and just dig into it with all her might, she loved it.

Your cast is all very talented, but they’re all different ages, they have different experience levels, they’re all known for very different things and different movies in their careers, how did they respond to this movie and the ideas in it?

I certainly didn’t twist anybody’s arm to do it. Again, Andrea’s writing I think just really drew people in, and Keira was a very easy yes. The Keira I had in mind when I approached her was the kind of “Bend It Like Beckham,” first “Pirates” movie Keira that I remember just being floored by back in the day. Just that incredible confidence that she had even at a very young age, and that ease in her own body, her physical comedy; she’s just so effervescent on the screen. She’s been doing contemporary roles, but I think the period pieces sort of loom large and so it’s just really lovely to see her take on this role and bring a lot of herself. I think what’s so great about Chloe and Kaitlyn Dever too, who plays her friend, they were both 16 when they shot the film. They’re so mature and they’re so professional, and Chloe’s got a lot of experience under her belt, and when you talk to her as a director it’s just like talking to a 30-year-old. You’re talking to an adult in terms of her professionalism. But the fact that she is a true teenager and whether she’s rolling her eyes at her dad or she’s giggling in the sleepover with her best friend, it was just immediately accessible. It was great to give Sam a role that, I think he was really excited to do it because he’s never really done that kind of thing before. You know, played a lawyer, played a dad of a teenager. Considering the long list of kind of disturbed, outright sociopathic people that he’s played … it was really fun to see this little dark edge and so much extra under the surface to this every day guy trying to get through life. And then Mark Webber’s character was really important to me, he plays Anthony, the boyfriend.

I was going to ask you about that. In movies, you usually don’t understand how they were together so long and it’s really obvious in this movie why those two characters were together but also why they had to break apart.

I’m really glad you said that. You can’t see, but you just gave me chills. It was a huge concern, and a lot of effort went into that very thing. I don’t want to make a movie where in the first five minutes you’re going, “Why is she hanging out with any of these people,” not understanding the relationships that exist, and just waiting for her to leave everybody. And also you lose respect for your main character if they’re hanging out with people who don’t have any kind of redeeming qualities to them. That was a big concern for me, that everybody feel lovable in some way, or at least you understood.