According to 2014’s movies, Laura Dern has given birth to Reese Witherspoon, Andrew Garfield and Shailene Woodley. Dern is 47, which means she had little Reese, who’s now 38, at age 9. For an onscreen mother-daughter duo, that age difference seems like it would ignite red flags. Yet it doesn’t matter one bit in “Wild,” which finds Witherspoon portraying Cheryl Strayed, who, in 1995, hiked the Pacific Crest Trail by herself after her mother’s death and recounted the experience in an Oprah-endorsed best-seller. Dern and Witherspoon’s familial chemistry is one of the many authentic elements of the big-screen adaptation, steered by “Dallas Buyers Club” director Jean-Marc Vallée and written by “High Fidelity” author Nick Hornby.

Dern had other mom roles this year in the teen weeper “The Fault in Our Stars” and indie festival hit “99 Homes.” “Wild” and “TFIOS” have placed Dern, the daughter of Diane Ladd and Bruce Dern, within reach of potential Oscar nominations. (“99 Homes” hasn’t yet hit theaters and therefore isn’t eligible this year.) It may seem like Dern is stuck in the supporting realm, but she doesn’t mind. The bubbly actress, who landed her first significant role at age 13 in the movie “Foxes,” cashed in on her leading-lady chip with HBO’s short-lived “Enlightened,” and her movie work in 2014 hasn’t left anyone wanting.

This year you played a mother who loses her daughter and a mother whose daughter loses her. Does living inside those two scripts bring you closer to your own mother at all?
Well, certainly, working on these two scripts, in all their differences and all their similarities, because the writers are so authentic. With John Green — who is such a beautiful man and a great writer — [“The Fault in Our Stars”] wasn’t his life story, but for him his writing was inspired by a real girl and her family, and so we wanted to pay tribute to his words in that way. “Wild” is an even more specific way to pay tribute to Cheryl and to [her mother, Bobbi], but certainly working on things that crack your heart open like this deepens all relationship, and I think it has made me want to make my mom know how loved she is even more. We’re very lucky to have a very loving and deep mother-daughter relationships; we’ve worked together many times and we’re very close. But still, in a new way through this story and through Bobbi’s incredible words, it makes you really want to be grateful for everything you have and the people you have.

Had you read the book first?
No, I did not. I was offered the part having heard of the book and since loving the book, but had not read it. And then I read the book and the script right after they offered it and spoke to Jean-Marc Vallée. He told me over Skype — because he was finishing his film “Dallas Buyers Club” and doing this and so we were on Skype together — and he described everything and then I read it and fell madly in love with Cheryl’s words and the story and Bobbi through her, and I spoke to Cheryl on the phone. The minute you read the book, you’re in forever.

After reading it, what sort of questions did you have for Cheryl about her mother? She died of cancer when Cheryl was 22, so I’m sure Cheryl herself still has so many questions, too.
For me the key was that the essence of the things she says never work in a Pollyanna tale. They profundity of them works and impacts the viewer and the reader because she’s earned her gratitude. We know she’s been through hell and she’s still willing to say, “Happy people sing,” and to want to find the gift in everything she’s walked through. That’s what’s so profound because if I wanted to learn more about anything, it was, “Tell me where she’s come from, I want to know everything she walked through to know how she got here.” And the people I know that really have a wisdom and humility and gratitude are most often the people who’ve been through the most. So it’s a really beautiful thing to learn from those people, to be reminded how lucky we are. But also I had to know as an actor everything she walked through to get her to the place that she could say those things and not say them lightly to her daughter, but say them because she wants them for herself. That’s what moves me so deeply about her.

Is hiking the Pacific Crest Trail something you could do if you were in a bad way like that?
No. [Laughs]

No hesitation whatsoever.
Let me be clear. If 10 of your friends and 10 of mine want to come and I can, like, go off and sit and stare at a lake for 10 minutes but we’re all camping together at all times, the idea of immersing myself in nature is really intriguing. But the alone part is an absolute no. I could never have been that brave. Forget it.

Did you and Reese know each other before “Wild”?
We’d only met socially, and very few times, but always really loved each other. We shared how much we admired each other’s work and we both started at a similar age, very young. We shared directors and similar actors, really close friends. We’re both from the South. We have a lot of commonality, but we’d never worked together, so it was a huge joy for me that she wanted me to be part of it and produced this and found the material. It is so her baby. She gives so much to people, from having fought to get this movie made the right way with the right filmmaker and to protect Cheryl so deeply. So I feel really, really lucky to be on the ride with her, but from the minute we got to play out this story, which just cracks your heart wide open, we’ve only known each other in a really deep, authentic way. We’ll be friends forever because there’s no cordial “hello.” We were two peers and women about to embark on needing to express the deepest kind of love story, and how fun for two actresses to do that. How rarified to share that kind of love story.

“The Comeback” has returned …
Yes! It’s so genius.

Does it give you more impetus to get “Enlightened” back on HBO, too?
Well, I’ve gotta say, now that it has returned, we can never say never. It’s nine and a half years later, so that’s exciting. I know that the story closed now, but I guess you never know. Oh my god. I would play Amy any day of the week. I just love her so much, so it would be impossible to say no to getting to be in her skin more, as excruciating as it is.

It’s such a visceral, uncomfortable experience, just like “The Comeback.”
Ah, I love it. Lucy was my hero. I was raised on “I Love Lucy,” so that’s my favorite kind of audience experience. So I love playing those kinds of characters and hope that, if not with ‘Enlightened,’ with other things, I get to explore that uncomfortableness in drama and comedy.”

Outside of “Enlightened,” it seems like you’ve only taken supporting roles lately. Are the right leading parts not out there right now?
I think a combination of a few things. I think that first off, until this last year, I dedicated — because I was a co-creator on “Enlightened,” too — three years of my life to that, so I really only had the time to do “The Master” and a few other things when I was able to leave and do smaller parts. It was the nature of making that kind of commitment to something. But with that said, the things that have been most exciting that I have been asked to do with filmmakers I love have been supporting roles. And they’re incredible roles. There’s no lead role that I can dream of playing that would mean more to me than playing Bobbi in “Wild,” for example, because I’m just so in love with this opportunity and love her so much. But certainly I would love to explore a character in the depths of the way I got to explore Amy. It made me rabid to do that again in a film, so now that I have the time hopefully the opportunity will come soon, too, where you’re just deeply delving into the character from beginning to end, because that’s a really fun thing to explore.

Is that what led to your football movie with Judd Apatow? I know you’re producing — are you acting in it, too?
Yes, I’ll definitely be acting in it as well, and it will be a really fun ensemble for a great group of women.

Are you a big football fan?
I am a huge fan of the world and I was raised by a huge football fan, being my father. And as an American and someone who spent a lot of time in the South with my own family, really the one deep ritual we had was the sports season. So that really interests me. What it gives us in our lives, that’s what I find really fun. And mostly — and we’re in really early stages about what is is and what it’s going to be — but mostly I’m just really excited to be on a journey with Judd Apatow because he explores the same world I’ve always loved being in, like with Alexander Payne and David Lynch, where it’s heartbreaking and funny and uncomfortable all at the same time. But he’s figured out a way to do it on a large scale and access a really wide audience who seem to really connect to it to, too, and that’s the kind of storytelling I really love.

“Wild” is currently playing in select theaters.