"I don't want to be into jihad no more," she added later. "I don't think like I used to think."
In imposing the sentence, U.S. District Judge Petrese B. Tucker acknowledged the woman's continued cooperation with federal investigators - assistance that has led to the conviction of two of her coconspirators and the indictment of her alleged terrorist handler.
Still, Tucker described their plot, a 2009 plan to kill Lars Vilks for his depiction of Muhammad on the body of a dog, as "gravely serious."
"We should all be thankful that the people she communicated with did not have the wherewithal to complete their mission," the judge said Monday. "Because the court has no doubt that, given the opportunity, she would have completed it."
Mark Wilson, LaRose's attorney, said his client's plan to kill Vilks was "more aspirational than operational," and questioned whether she could have carried out the crime.
Prosecutors maintained that she had taken detailed steps to carry out the assassination, including flying to Amsterdam, tracking the artists' schedule, and deciding how many times she would need to shoot him to cause death.
In an interview Monday, Vilks told the Swedish news agency TT that he had mixed feelings about the punishment.
"That's a pretty tough sentence," he said. Previously, he said he felt LaRose should have been released on time served.
Still, four years after her arrest, LaRose's case remains significant. With her blond hair, blue eyes, and deep Southern twang, she garnered international attention and changed U.S. officials' expectations of what to fear from homegrown terrorist threats, prosecutors said.
She remains one of only a few women in the country to have been charged with terrorism in federal court. But that is exactly what made her attractive to Ali Charaf Damache, a cell leader who recruited LaRose over the Internet, prosecutors said.
Damache, who remains in custody in Ireland fighting extradition to the United States, allegedly targeted others who did not fit the typical terrorist profile, including Jamie Paulin-Ramirez, a single mother from Colorado who flew to Ireland to marry Damache, and Mohammad Hassan Khalid, a former high school student from a Maryland suburb who is the youngest person ever to be convicted in the United States on terrorism charges. He was just 15 when he began chatting with LaRose online.
But few embraced Damache's cause with the gusto of LaRose, said Assistant U.S. Attorney Jennifer Arbittier Williams. In online jihadist forums, she expressed disgust over the failure of Muslim men across the world to act. She actively raised money for other terrorist plots with an efficiency that earned her the nickname "the Hunter" among her compatriots.
"It was scary for many people to think that Ms. LaRose could be radicalized, just online, in the United States," Williams said. "There are other people like that out there in the country and in the world."
Even as she addressed the court Monday, LaRose spoke of Damache with an adulation that has prompted prosecutors to argue that she remains a threat.
"I had so much respect for him. I had this emotional attachment to him," she said. "He was so brave."
Wilson said his client's complicated relationship could only be understood through the lens of her troubled past.
Physically abused by her mother and stepfather starting at age 8, continuously raped by her father, she ran away at 13 and began prostituting herself in North Texas. At 16, she used a forged birth certificate to marry one of her customers - a relationship that quickly soured.
A later marriage led to drug and alcohol addiction. And by 2002, she found herself living in Pennsburg with a frequently absent boyfriend, his cancer-stricken father, and her own mother, whose mind had been lost to dementia.
During a fight with her boyfriend while vacationing in the Netherlands, LaRose met a Muslim man at a hotel bar. It took only that one encounter to convince her that Islam held the answers she was looking for, Wilson said.
LaRose told the court that her new religious views became radicalized after watching online videos of violent clashes between Israelis and Palestinians.
"We was watching videos of men and women and children being killed and all the screaming," she said during Monday's hearing. "I stopped learning Islam like I was supposed to, and I went straight to jihad."
LaRose told the judge that years later, when Damache assigned her the task of killing Vilks, she found the male validation she had sought for most of her life.
She traveled to Amsterdam, then Ireland, to carry out the deed, but left the terror cell after only six weeks. She called an FBI tip line seeking the money to return home.
Because she has remained behind bars since her 2009 arrest, LaRose could become eligible for release within five years. In addition to her prison term, she must submit to five years' court supervision, pay a $2,500 fine, and undergo substance abuse and mental counseling in prison, the judge ruled.
As Monday's hearing concluded, Tucker, while sympathetic to LaRose's story, still appeared unnerved.
"That out of boredom or out of being housebound, she hatched this mission," the judge said, "is just unbelievable to this court."