Hannah opens up about her upcoming wedding, being airbrushed, the best career advice she's received, and much more.

Credit: James White

Before Hannah Davis was a Sports Illustrated Swimsuit cover model, before she appeared in a red Ferrari alongside the Griswold family car in the movie remake of Vacation, before she was hosting Project Runway: Junior, she was wearing boys' clothes to school.

"I was best friends with my brother; I always kinda wanted to be what he was," recalled Hannah, 25. So she'd rock his cargo pants and sneakers. "I looked like a little boy, so I just embraced it," she says.

Hannah—the youngest of three kids—was raised on St. Thomas in the U.S. Virgin Islands. In fact, barefoot in faded Levi's shorts, she might have just stepped off that island. Oh, and she's wearing one more thing: a big round engagement ring from her fiancé, retired New York Yankee Derek Jeter, 41.

"I love it," says Hannah. "I just can't stop staring at it."

Now, as she prepares for her wedding, Hannah opens up about being airbrushed, what makes a relationship work, and the genius career advice she got from her mom.

You grew up on St. Thomas. Are you still an island girl at heart?

I'm pretty easygoing. I don't like high stress. It was definitely a change when I got to New York because I was late for everything. And I remember someone told me, "You know, when you're late, it's like you have no regard for that person's time." And I was like, "Oh, wow!" I didn't look at it like that.

You have such a good vibe with the kids on Project Runway: Junior.

I love them so much! You'll see, if you watch the show, I cry a lot because these kids are so talented, and you don't want anyone to go home.

What makes you cry in the real world?

I'm pretty tough. I don't cry often. But when I do, I lose my s—t. Funerals set me off. Weddings. When I see the bride walking with her dad—that was the trigger at my sister's wedding; I started bawling.

What's going to happen at your wedding? Will you hold it together?

I think I'll be fine. I can't even begin to think—I don't wanna psych myself out about it.

What sort of bride are you so far?

I'm chill. I just want it to be a fun day, not all the fuss. I don't want to go overboard—it's not about the place settings. I won't get stressed-out about that, 'cause I could just care less.

You became a model at 14. How did you start?

I was playing on the Caribbean tennis circuit, so I was going to a lot of U.S. tournaments. IMG and Ford were at these tournaments, so that sparked my interest because I felt like, 'OK, maybe I can pay for my lessons.' I looked at it purely as a job to help pay for my dream.

What was the biggest setback you've faced?

When I was playing tennis, I was 15 and in the best shape of my life, so I ate whatever I wanted. When I moved to New York [to model], my body started changing because I was no longer playing tennis and training like I used to, and I was away from home for the first time. So I was like, "Oh, I'll just order pizza every night."

How much did you gain? Like a freshman 15?

Probably about that. It looked so silly on me; I was a bloated version of myself. I tried as hard as I could to maintain a modelesque body type, but I realized I had grown out of it. It just wasn't attainable anymore because it's not what my body wanted to do. My agents wanted me to do Fashion Week in Milan, and I knew I didn't look like the rest of the girls. I credit my mom because she always told me, 'Oh, if they don't want you, who cares? You'll find someone who does.'

Do you still stick to your mom's advice?

Yeah, absolutely. Because you get a little backlash once in awhile—maybe they want you to slim down for something. But now it's like, 'Sorry, I don't care. If you don't want to work with me, that's OK with me.' It's not a cocky thing; I'm just more concerned with my quality of life. I don't want to go to birthday parties and not eat cake, and I think that has made me in better shape in some ways.

Is there a swimsuit style you just can't wear?

I can't do those high-waisted, boy-shorty ones that hit you a little higher, that are kind of in right now? I feel like I'm wearing hiked-up volleyball shorts.

Have you ever been Photoshopped too much?

Yes, many times—but I won't tell you, because I'll never work again! [Laughs] But it's not a big deal; maybe they just wanted it a little bit more airbrushed-looking, and that's their style. I've never had anyone alter my face. They've only sort of smoothed things out. I think you look like a Barbie doll when they erase the wrinkles under your eyes. I don't mind if there's a crease when I smile. They're just creases. They're fine—leave 'em!

How do you prep for a bikini shoot?

Uh, I'm pretty much miserable! I warn everyone, 'Prepare for me to write you a random bitchy text because I'm hungry.' I do eat the whole time, but I work out a lot, usually two workouts a day for two or three days before. I'll go on a 10-mile bike ride or something, and then I'll come back and work with a trainer. I do pretty intense workouts in the gym.

What kind of workouts?

So, I hate running. I love sports—I could play flag football or basketball all day long—but ask me to get on a treadmill, I hate it. But I've been doing sprints now; I sprint for a minute, I've got a 30-second break, and then I sprint for a minute.

What makes your fiancé, Derek, right for you?

I think finding someone you truly don't have to change for—not even a single part of you—makes you rise to the occasion. You want to find someone who is way better than you, or you think so. You're like, 'This person is gonna bring out the best in me, and I'm gonna be a way better person this year.'

And what type of friend are you?

I'm the mommy. I'm the one saying, 'I don't know if you should be hanging out with that person.' In my work life, I'm pretty easygoing. If someone says, 'Put this on,' I'm like 'OK, fine.' But in my personal life, I'm super protective. If I don't feel like you're a good influence on my girlfriend? Oh yes, you will know.

Hannah's insidery look-amazing tips:

How to buy a better bikini: "People think that if you wear giant bottoms, you can have full coverage. But full coverage makes everyone look wider! Less is more in a lot of cases. The string ones you can wear forever because you can adjust the sides—you go on vacation, you're having fun, you're like, 'OK, I'm gonna loosen this up a little bit.'"

How to take a selfie you love: "You always wanna feel the light on your face. It's the photographer's rule: Find the light. It's so corny, but even if you're in your apartment, go around—wherever the lightbulb is. It's where I want my phone."

How to treat sun spots at home: "I use Greek yogurt, lemon, and a drop of honey. I leave it on until I can't stand it anymore. It hydrates, and I believe the lemon helps with dark spots. I grew up in the sun, so I'm always concerned with freckles."