For years, Bella didn’t dare speak to colleagues about the depression, anxiety, and Lyme disease, with its rotary cannon of physical and cognitive symptoms, that have pursued her since early adolescence. She blames a habit of people-pleasing but does not let the fashion world, possessed of what she views as a “don’t ask don’t tell” attitude about mental health, off the hook. “For three years while I was working, I would wake up every morning hysterical, in tears, alone,” she recalls. “I wouldn’t show anybody that. I would go to work, cry at lunch in my little greenroom, finish my day, go to whatever random little hotel I was in for the night, cry again, wake up in the morning, and do the same thing.”

Even now, no matter how she is feeling, Bella’s default setting at work is good cheer, gameness, rigorous professionalism. Having some preconceived notions of my own, I admit I was surprised when a stylist friend told me that Bella is invariably lovely to work with. A veteran executive at a modeling agency that does not represent her told me, with maybe a little professional jealousy, that she enjoys a flawless reputation in the industry. “There is a myth that models arrive fully formed. It’s not true,” he explained to me. “The greats become great over time, and Bella, through very hard work, has gotten great. She is up for everything: campaigns that can’t pay her, small magazines, shows that any agent would tell her to pass on. Some of the girls in her cohort, who have gotten so rich and famous—are they even models? Do they love fashion? The irony is that she turns out to be the star of her generation.”

But if there is an irony in her success, no one feels it more keenly than Bella herself. She has failed the purity test of the true unknown discovered in a shopping mall in São Paulo or Minsk. She understands that there are those who believe she parlayed a privileged upbringing into a career in fashion, that she hitched a ride on the glamorous coattails of her older sister, Gigi Hadid. She knows that there are people who think that her face and body are the products of cosmetic witchcraft.

The fashion world is possessed of what she calls a “don’t ask, don’t tell” attitude about mental health. Miu Miu sweater, shirt, skirt, briefs, and belt.

“I was the uglier sister. I was the brunette. I wasn’t as cool as Gigi, not as outgoing,” she recalls. “That’s really what people said about me. And unfortunately when you get told things so many times, you do just believe it. I always ask myself, how did a girl with incredible insecurities, anxiety, depression, body-image issues, eating issues, who hates to be touched, who has intense social anxiety—what was I doing getting into this business? But over the years I became a good actress. I put on a very smiley face, or a very strong face. I always felt like I had something to prove. People can say anything about how I look, about how I talk, about how I act. But in seven years I never missed a job, canceled a job, was late to a job. No one can ever say that I don’t work my ass off.”

Isabella Khair Hadid was born at Georgetown Hospital in Washington, D.C., with her eyes open, not crying. Her mother, the Dutch-born former model Yolanda Hadid, likes to say that she came out of the womb holding a cigarette and a martini. Her father is Mohamed Hadid, a Palestinian who fled to Syria with his parents during the war in 1948 before settling in the D.C. area. He took architecture classes at MIT and became a real estate developer, mainly in Beverly Hills, where the family moved when Bella was a toddler. Her parents separated when she was three, and Bella, Gigi, and their younger brother, Anwar, were raised in Santa Barbara. They relocated to Malibu when Bella was in the seventh grade.

Bella says that on account of multiple childhood traumas, about which she prefers to say no more, she does not remember broad swaths of her early years. She finds this somewhat embarrassing. But she remembers riding horses as soon as she could walk. She remembers a relaxed country life in Santa Barbara, removed from the glitz of Montecito. Yolanda insisted that she make her bed every morning. Likewise, she explains that the Malibu she inhabited was by and large a hippie surfer hamlet, not a gold chain of billionaire beach houses. At 14, she got a job at SunLife, a juice shop in Point Dume, paying $7 an hour. “It’s not to say that I didn’t have a very privileged upbringing,” she explains. “But my parents are immigrants who came here and worked for everything they had. I always knew the value of a dollar.” She had a thing for clothes, however: Betsey Johnson, vintage tees, Levi’s, plaid shirts. Did she borrow a friend’s Alaïa dress for prom? Sure. But every second Sunday of the month, she drove to the Rose Bowl flea market to thrift.