Two years ago, as she waited to know whether she'd be found guilty of murdering her British roommate, Amanda Knox was so confident she thought she'd be flying home to Seattle within hours.

Still behind bars, the American is a changed woman, family and friends say _ more mature, more wary of people around her, increasingly anxious as an appeals court verdict approaches.

The transformation they describe is seen on the outside. Gone are the Beatles t-shirt, the cocky demeanor, the irreverent smile. Now 24, Knox is conservatively dressed, thinner, clearly worn out _ although detractors say she's merely putting on an act.

"When she walked in for the (2009) verdict she was actually happy," says her friend Madison Paxton, "like she thought she was going to be on a plane home in 12 hours, and was running to the courtroom. She wasn't even remotely prepared for what she heard."

"This time you see it manifest in her body and the way she physically responds to it _ she is ... terrified," Paxton told The Associated Press, sipping an iced cappuccino in a bar in Perugia, a stone's throw from the courthouse.

Knox was convicted of sexually assaulting and murdering Meredith Kercher, a British student in Perugia, and sentenced to 26 years in prison. Co-defendant Raffaele Sollecito, an Italian who was Knox's boyfriend at the time of the crime, was convicted of the same charges and sentenced to 25 years. Sollecito has also appealed.

One person unconvinced by Knox's new image is the lawyer of a man she unjustly accused in the early stages of the investigation.

Carlo Pacelli told the appeals court this week that Knox has a "talent for lying" and is an "experienced actress." Over the course of two hours, Pacelli called Knox a "demonic, satanic, diabolical she-devil," and "spell-casting witch, a virtuoso of deceit."

Pacelli's client, Diya "Patrick" Lumumba, was unjustly accused by Knox of being the murderer and was briefly jailed as a result of that claim. Knox maintains police pressure led her to accuse Lumumba, a Congolese national in whose bar in Perugia she occasionally worked.

Knox will know her fate within a week: She hopes to be freed after four years in jail, her accusers are asking the court to stiffen her penalty to life in prison.

The appeals court may issue a decision as soon as Saturday, capping a nine-month trial where Knox has appeared at times tense, worn-out and tearful. Paxton says she can't eat or sleep properly as the date of the verdict approaches.

When she entered the spotlight in 2007, with her fair hair, blue eyes and photogenic looks, Knox immediately fascinated audiences. Some called her an "angel face" devil, others saw a naive innocent caught in a catastrophic judicial mistake. British tabloids took to calling her "Foxy Knoxy" _ an old nickname that didn't help her image even as her family insisted it stemmed from her skillful moves on the football pitch.

Throughout the case, depending on whom you asked, she was a femme fatale or a naive, lovestruck girl. Recently a defense lawyer likened her to Jessica Rabbit _ not bad, just drawn that way.

With her life dissected in countless articles, books and even some movies, Paxton says, Knox "has had to learn how to not rely so much of what other people say about her" _ an experience that has made her stronger and at peace with herself.

During the first trial, she would smile to the court, and keep a breezy, even flippant behavior throughout hearings that inevitably discussed a gruesome murder. In her first public statement to the court, Knox took on a casual, almost amused tone in discussing the presence of a sex toy _ a pink rabbit-shaped vibrator _ in the Perugia house she shared with the victim.

"It was a joke," she said then, gesturing with her hands to indicate the size of the toy.

Even as her family maintained she was always respectful and aware of the seriousness of the charges against her, Knox's behavior didn't help her cause in the eyes of Italian public opinion.

Now, she looks down as she enters the court. In recent hearings she held her hands clasped in front of her face as if praying. She has abandoned the "All You Need is Love" T-shirt she once wore in court for Valentine's Day for satin blouses and black trousers.

Early into the appeals trial, she gave her longest, more passionate defense to date, saying with tears in her eyes she hadn't killed Kercher, who was a friend she had been honored to meet.

Skeptics argue that this time around, she is being carefully coached to come across as sober and humble.

"Some investigators do believe that she has been told about the negative publicity and headlines which initially her relaxed manner in court prompted," said John Follain, author of the forthcoming book "Death in Perugia."

"They have noted this change in behavior which they believe is part of her defense strategy to portray her as a more settled, more mature young woman. Of course anybody would change in four years, especially four years in prison," said Follain, who has covered the case for the past four years.

Knox still commands attention. Flashlights and cameras are all for her as she enters the courtroom, with reporters trying to get a glimpse of her past the wall of cameramen.

Those who are close to her say the changes go deeper than just appearances.

"She's been in prison for one sixth of her life," her father Curt Knox noted in a recent interview. "She's obviously matured very much in prison."

One main change, her father says, is that Knox has lost what he said was her ability to trust people.

"No matter who you were, no matter how you looked she always thought there was good in you," her Curt Knox said. Now she "really does not have that same trust level."

In prison, Knox spends her time reading, doing work with fellow inmates, studying German and creative writing, says Paxton, a friend from the University of Washington who has for a year moved to Perugia and visits Knox in prison six times a month. Reports describe her as a model prisoner.

Knox keeps in touch with Sollecito through letters to comfort each other, but the two are no longer romantically involved.