By Alex Tresniowski
October 17, 2011 12:00 PM

For a moment it looked like Amanda Knox might faint. She stood behind the defense table in a packed Perugia, Italy, courtroom on Oct. 3 and tried to address the jury, but the weight of the situation seemed too much to bear. “You can remain seated,” Judge Claudio Pratillo Hellmann offered, but Knox, pale and slender, stayed on her feet. Then she took a deep breath, told herself “okay” and made a plea for her freedom. “I am not who they say I am,” she declared in fluent Italian. “I am innocent.”

Later that day-and after a nightmarish four-year ordeal that began when her roommate Meredith Kercher was found dead in their apartment in November 2007-Amanda Knox’s conviction for murder was overturned on appeal, and she was finally set free. The pretty, athletic exchange student from Seattle-called a sex-crazed, satanic murderess in Italian tabloids-sobbed with relief as court officers whisked her away after the decision and was soon reunited with her family. They spent the night in a rented countryside home and flew back to the U.S. out of Rome on Oct. 4. In a letter to supporters, Knox-who faced 26 years in prison-thanked those “who shared my suffering and helped me survive with hope.” Meanwhile Kercher’s brother Lyle said his family accepted the decision but wondered how a ruling that “was so certain two years ago has been so emphatically overturned.” Their search for justice, said Lyle, is “back at square one.”

The decision capped a grueling and often desperate journey for Knox, 24, and for her family. In exclusive interviews with PEOPLE in the days before the verdict, Knox’s mother, father, stepfather and sisters painted an intimate portrait of her life in prison, the measures she took to stave off despair and what she will do once she returns to Seattle and resumes her life. “We won’t know the extent to which Amanda has changed until she comes home,” says her mother, Edda Mellas, 49, a schoolteacher, who was in Perugia for the verdict. “But I am most proud that in this time of pain, she has maintained her dignity and strength. She has survived something horrible.”

Knox’s life changed forever on Nov. 2, 2007, when police found the body of 21-year-old Meredith Kercher, her throat slashed, in the Perugia apartment she shared with Knox. The evidence that Knox was involved was slight: primarily, a minuscule amount of her DNA on a kitchen knife that the prosecution claimed was the murder weapon. Still, investigators charged Knox, her then-boyfriend, Raffaele Sollecito, 27, and another man, Rudy Guede, 24, with murder, and all three were found guilty. The verdict “was total devastation for Amanda,” says her father, Curt Knox. “She is someone who wouldn’t kill a spider.”

By the time of the verdict, Knox had already spent two years in Perugia’s Capanne prison and had developed the rituals that sustained her throughout her ordeal. On most days she spent 22 hours inside an 18-ft.-by-13-ft. cell she shared with at least one and sometimes as many as three inmates. The cell had one bathroom, a small TV and an electric pan cooker; Knox added a tiny radio she bought for $20 at a prison shop. “Amanda would wake up early, make herself coffee, then go out for one of her two hours of outdoor time,” says her mother. Knox tried to stay fit by walking in the 30-ft.-by-30-ft. courtyard and doing sit-ups and push-ups in her cell. Still, she lost so much weight during her imprisonment that she dropped from a size 6 to a 0.

Despite stress and bouts of sleeplessness, Knox “had a schedule, which she maintained; she didn’t just lay in bed all day like some inmates,” says her stepfather Chris Mellas, who helped raise her since she was 9. “She made a point of washing, changing her clothes, looking after herself. She tried to maintain a certain degree of dignity.” Knox had only a handful of possessions-a few books, four CDs, some clothing-but still “she cleaned her cell frequently,” says Chris. “She’s a bit of a neatnik.”

A huge source of comfort was her limited contact with friends and family; she was allowed eight 1-hour visits and four 10-minute phone calls per month. Knox has three sisters-Deanna, 22, Ashley, 16, and Delaney, 13-and “she hasn’t been able to see them grow up, so we tried to tell her as much as we could to allow her to be a part of it,” says Curt. Knox’s visitors at the prison were allowed to sit around a table with her, though “usually we’d push it out of the way and sit in a circle holding hands or hugging,” says Chris. “Her friend Madison would braid her hair, and I’d give her hand massages.” Between visits Knox sent dozens of letters home. “My most dearest Bean, I love you, how are you?” she wrote to Delaney this August. “I’m so anxious for the end of my appeal. I feel itchy with waiting…. I’m afraid, but ok.”

A linguistics major at the University of Washington who had moved to Perugia for her junior year abroad, Knox also tried to keep up with her studies and “had been sending in her course work,” says her mother. But after the guilty verdict in 2009, her concentration waned. “She was depressed and thinking, ‘Am I going to be here for 26 years?’ ” Even so, say those close to her, Knox bounced back quickly from her darker moments and kept busy painting watercolors and playing guitar in the prison chapel. “She loved it when the nuns brought in the children of the other inmates,” says Chris. “They climbed all over her and hugged her. That was one of her favorite moments of the week.”

What really kept her going was the prospect of her appeal, which got under way last fall. This July her hopes were raised when a panel of court-appointed experts testified that police forensic scientists made glaring errors, rendering the evidence against Knox “inconclusive.” The DNA samples, the experts said, might have been mishandled, making it impossible to match them to Knox with any certainty. Yet in their final statements, prosecutors stood by the evidence and their depiction of Knox and Sollecito as sex-and drug-addled killers. “They have murdered,” said prosecutor Manuela Comodi. “And they have killed for nothing. And for this they must be condemned to the maximum sentence.”

Finally, late on Oct. 3, a jury of six lay people and two judges handed down their decision. In the tense courtroom, Knox bowed her head while waiting to hear her fate. The decision was split: Jurors upheld her conviction for slander, for falsely accusing bar owner Patrick Lumumba of the crime in 2007. But they overturned all the other charges, meaning Knox was free (Sollecito was also released; Guede remains in prison). “We are thankful Amanda’s nightmare is over,” her sister Deanna read in a statement outside the courtroom.

The prosecution claims that the decision left several questions unanswered and room for doubt about Knox’s innocence. Why did she tell police Lumumba was involved, and in the process implicate herself? Why did she act so dispassionately in the days after Kercher’s murder, blithely sitting in Sollecito’s lap and doing cartwheels in the police station? Knox has claimed police pressured her into implicating Lumumba, and that she was interrogated in a foreign language with no lawyer present. The prosecution’s portrayal of her as some kind of cold-blooded menace, says her stepfather, is just plain wrong. “Before this happened, Amanda never had any issues or problems,” says Chris. “Her life was school, soccer, friends.”

Knox’s parents, who estimate they have borrowed more than $700,000 for her legal fees and even more for their expenses, are looking forward, not back. They realize, however, that it will take a while to make up for all the time and all the moments they have lost. “We celebrated her 21st birthday without her,” says Curt. “But I have a whole checklist of things we purposely postponed until she gets home.” What will they do first once Knox is back? “Eat a slice of chocolate birthday cake,” says her sister Delaney. “Give her a hug and then go rock climbing, because she loves it and I want her to teach me,” says Ashley. “I know exactly what she will do first,” says Chris. “Go to the backyard and lay on the grass”-something Knox, confined to a concrete courtyard, hasn’t done in four years.

How quickly she can rebuild her shattered life depends on how much her prison ordeal has changed her. Once trusting to a fault, she has become “much more guarded,” says her mother. “She has had her idealism taken away,” says her friend Jessica Nichols. Knox has been so affected by what happened that after finishing her studies, she might even “become an advocate for people who are wrongly imprisoned,” says Curt.

But such decisions can wait; for now, Knox will focus on the simple joys of freedom. “Being with her family, catching up, seeing her two cousins, who were babies when she left,” says her mother. “And she says she never wants to be behind another locked door, ever, in her life.”