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"Let me just stuff my phone in my bra, and we're ready!" Hilary Du￿ff says, adjusting her boobs. iPhone secure, she leads me out of her Beverly Hills home into its backyard and through a secret gate that opens directly into a park, the starting point of our hike.

Du￿ff is on the move. It's been a decade since her hit Disney series Lizzie McGuire wrapped. On March 31, she returns to your regularly scheduled programming in TV Land's Younger, created by Sex and the City's Darren Star. Those expecting a G-rated Duff￿ need not look here. Her character, Kelsey, dater of douche bags and teller of masturbation jokes, is less Lizzie, more Liz McG — Lizzie's post-collegiate, corporate ladder-climbing alter ego. "Maybe she parties too much," Duff￿ says. "She'll go out, have too many, then wake up and scramble to the office. She's wickedly driven." Ah, yes, we all know and love a Kelsey.

But Duff￿, 27, initially resisted the project as it meant moving with her 2-year-old son, Luca, to New York soon after separating from her husband of three years, hockey pro Mike Comrie. "I didn't think I could do it," she admits, cutting across a ditch and onto a wooded trail. "I was in a funky place." A call from Star led her to reconsider. "I couldn't really turn it down. [Kelsey] is grown-up but makes a shit ton of mistakes, which I loved. I didn't get to make many mistakes publicly in my life. I was always concerned with what people would think."

Du￿ff was only 14 when Lizzie McGuire made her the hypothetical BFF of millions. Although the show ran for just two seasons, it spawned a box-offi￿ce hit — 2003's The Lizzie McGuire Movie opened second only to X-Men 2 — and a generation of Lizzie loyalists who'd go on to support Du￿ff's multiplatinum pop-music career.

Still, it hasn't been easy for fans to see Du￿ff as anything but squeaky-clean. "As a person who grew up with Hilary Du￿ff," starts one YouTube comment on a clip of Younger, "am I the only one who feels weird hearing her talking about doing stuff￿ to someone's 'special place'?" He or she must have missed Du￿ff's threesome on Gossip Girl. However, Duff￿ says she doesn't consciously look for roles to spice up her image. "I don't have to prove to people that I'm an adult now. I am an adult. It's frustrating to be put in a box, but I never needed to wild out to show that I'm grown-up."

Indeed, Duff's cut a quieter path than other Disney stars of her era: See Miley Cyrus, who's all but buried Hannah Montana in marijuana-print leotards, or Lindsay Lohan, Parent Trap star turned Oprah bait. For Du￿ff, going o￿ff the rails wasn't an option. "At 19, I did a massive friend cleanse. That was really hard, to sit down with people and say 'We can't be friends anymore.' They were like 'That's fucked up; you're a bitch.' But having a good reputation was important to me. That's not to say I didn't screw up and do little naughties here and there."

She hinted at one such naughty in last summer's single "All About You," which starts, "You could be my dirty secret." Is Du￿ff the type to have an F￿ buddy? "I wrote that song for a reason!" she says, as we hu￿ff and puff￿ up the mountain. "I've enjoyed myself. I think everyone should have something where you know it's not exactly what you're looking for but you just have a wicked good time. That was really freeing for me and a bit of an awakening. It's fun to have a secret."

People have always wondered about Du￿ff's sex life, mainly when, exactly, she swiped in her V card. "I had a 26-year-old boyfriend," she says, referring to Good Charlotte's Joel Madden, who she started dating when she was a teen. "So everyone can make their own assumptions about what I was doing." Madden is now married to Nicole Richie. But another of Du￿ff's famous exes, Aaron Carter, has yet to move on.

Last year, after posting a picture of Du￿ff, he tweeted, "Don't be that stupid douche who loses the love of his life forever. Like me..." FYI: They dated when they were 13. "Him reaching out through social media? It's ridiculous!" she laughs. "But then people do it all the time, like Chris Brown and Karrueche? Come on, guys. Keep it between text messages."

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Keeping things classy is Du￿ff's MO. Even her split from Comrie in January 2014 has been by all accounts amicable. I commend her for having a drama-free separation. "Did we?" she asks. "We ... you're right ... compared to others. It wasn't working well enough to stay together, but there was still a lot of love involved. It was just a slow set-in of us not being the match that we used to be. I'm lucky for the person he is and I am and how we decided to handle this."

Wife life was something Duff had long dreamed about. "Mike and I were very in love when we met. We both really wanted to get married." They said "I do" when Duff was 22. "I'd been working since the age of 11 or 12, so making that choice at a young age seemed right for me. Maybe it wasn't, but we spent the majority of our time together really happy." Her view on forever-after has since shifted. "I don't want to sound bitter because I'm definitely not, but I don't know if people are meant to be together forever. Things happen over a long relationship that you can't always fight. A marriage of 20 years, the accomplishment of that must feel really great, but there are also huge sacrifices. I just always want to fight for happiness."

As tough as marriage is, Duff￿ isn't exactly pining for the freedom of her single days. "I had a pretty serious relationship at a young age that I ended, and it wrecked me for a good year and a half," she says, likely speaking of Madden. "I didn't really enjoy being single. My nature is happier being with someone and creating a deep friendship. Also the love aspect is super important, where you are really attracted to that person," she sighs. "It's hard to find that, all wrapped up into one."

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Du￿ff's the first to admit that she's figuring some stu￿ff out right now, and it's a process, not an achievement. She sees a therapist whenever she needs "a little tune-up." As for what she's learning? "Being in touch with what feels good and what doesn't. Sometimes I'll go down an Instagram hole, and all of a sudden, I feel weird about my career or life. I'm like, 'Take a break.' I'm a huge Instagrammer. I love it, but probably once a week, I've gotta put that down." If only we could all be so strong.

We're almost back to Du￿ff's house when she stops at a clearing overlooking L.A. "I swear this is soul-cleansing," she says. "Your problems become easier to work through, because in the grand scheme of things, they're not that big of a deal. Hiking helps me so much. My girlfriends are helpful." She turns to get a good look at the vista and smiles. "Wine is helpful too. Now, should we take a selfie?"

This article was originally published as "Vote for Hilary" in the April 2015 issue of Cosmopolitan. Click here to get the issue in the iTunes store!