"Tallulah was pretty much given an ultimatum," a family insider tells PEOPLE in the magazine's new issue. "Her parents were about to take away everything from her."
Amid reports that the youngest daughter of Demi Moore and Bruce Willis is in rehab, multiple sources confirm to PEOPLE that the 20-year-old is getting help. Her troubles go back years: A source says she was "adversely affected" by her parents' divorce in 2000 and a former high school classmate says her mother's hospitalization and subsequent rehab stint in 2012 also weighed heavily on her.
"When Demi was hospitalized, Tallulah didn't show up to school for days because she was too embarrassed," the classmate says. "She was very open about Demi's issues and would sort of imply, 'Of course I have issues too, look at my mom.' "
In a video interview recorded earlier this year, Tallulah opened up to StyleLikeU about her longtime insecurities about her looks, saying she had been diagnosed with body dysmorphia. Another source says she seemed "lost," adding, "The constant and self-centered worry over her looks mirrors her mother."
Sources say that both Moore and Willis have visited Tallulah at a treatment center, but the Moore source says the parents have two very different approaches to the crisis.
"If Bruce suspected that Tallulah had any kind of substance abuse problem, he would have demanded for her to get help," the Moore source says. "Demi's take is that Tallulah is still very young and trying to find herself."
Reporting by PERNILLA CEDENHEIM, JENNIFER GARCIA, MARY GREEN and LINDA MARX
For more on Bruce Willis and Demi Moore's battle to get their daughter healthy, pick up the new issue of PEOPLE, on newsstands Friday