HALIFAX -- The family of Lindsay Souvannarath, the American woman sentenced to life in prison for plotting a Valentine's Day shooting rampage at a Halifax mall, says she would never have carried out the murderous plan.

In a newly released letter written to a Nova Scotia judge, her parents describe her as a sad and lonely person who is sensitive and not capable of violence.

Phyllis and Chanthaboun Souvannarath said she wanted very much to have friends but was rejected by her peers, bullied in school and struggled with being biracial.

"Lindsay never would have carried out the plan she discussed online with James Gamble," they said. "We know in our hearts that it was her loneliness and desire for friends that led to her online relationship."

The Facebook conversation between Souvannarath and Gamble, which started on Dec. 21, 2014, and ended on Feb. 13, 2015, quickly devolved into a shared admiration of the Columbine shooters, mass killings and a murderous conspiracy to open fire at the food court of the Halifax Shopping Centre.

The online messages expose gruesome details about the foiled plot to kill as many people as possible with Molotov cocktails, guns and knifes before committing suicide.

Police thwarted the plan after receiving an anonymous tip.

Gamble killed himself in his Halifax-area home, while Souvannarath was arrested at the airport and later pleaded guilty to conspiracy to commit murder. A third accomplice, described as the "cheerleader" of the plot, was sentenced to a decade in jail.

Nova Scotia Supreme Court Justice Peter Rosinski asked Souvannarath before her sentencing last week if she would like to address the court. She said: "I decline."

The judge said in his decision that the sentence -- life in prison with no chance of parole for a decade -- reflects her failure to express remorse or renounce the ideological motivations for the conspiracy.

Those ideological motivations included an obsession with Eric Harris and Dylan Klebold, two teenage gunmen who killed students and a teacher at Columbine High School.

Souvannarath's parents said the mass shooting in Littleton, Colo., deeply affected her.

"Her first grade teacher gave a graphic and inappropriate description of the Columbine shooting that left Lindsay terrified and unable to sleep alone," they said.

"We had to sit with her until she fell asleep for a few nights afterward."

The letter, entered as an exhibit in the case, details Souvannarath's struggle with being of mixed race.

"Lindsay always has struggled with the fact that she's biracial," her parents wrote. "When she was just four years old she came to us crying, saying she was sad because she did not look like her mom."

Souvannarath's mother appears to be white, while a Facebook account that appears to belong to her father indicates he is originally from Southeast Asia.

Her parents said when she attended a summer camp in Chicago with mostly African-American children, she happily declared "Look, Mommy! Those kids look just like me."

When Souvannarath was seven, the family moved from Chicago to a suburb that was "not very diverse or tolerant," her parents wrote.

During a recent phone call, her parents say she opened up about her difficulty being biracial.

"She usually keeps her feelings pent up, and I was very pleased to see that she was willing to talk about this matter," her parents said.

They said her elementary school teachers called her "delightful and imaginative" but that she started facing bullying in middle school.

Her parents said her appearance, coupled with her unique personality, made her a target for bullying and exclusion.

"She is very awkward socially and this has made it difficult for her to make friends," they said, adding that she was "without friends for most of her teen and young adult years."

Her parents said despite her high IQ, Souvannarath is "emotionally immature" and childlike in many ways.

"Up until this awful incident, Lindsay never caused any trouble for us," they said. "She has always been a good girl."

They added: "We were completely shocked when we learned what happened."

Souvannarath, now 26, is expected to be transferred to a prison in southern Ontario. After credit for time served in custody, she will be eligible for parole in seven years.

Her parents said they will likely move back to Chicago, where there are abundant resources for ex-offenders.

They said they will be there "to support and guide her" whenever she is released.

"We will make sure she gets the help and support she needs," they wrote.

However, the sentence of life in prison means she could spend the rest of her days behind bars.

Souvannarath's grandmother and grandfather also wrote letters to the judge ahead of sentencing. The handwritten notes were entered as exhibits in the case and made available Monday.

Her grandmother said she believes Souvannarath was never accept in the Midwest suburb of Geneva because "she looked a little different."

"Lindsay had dark hair and Asian features," she wrote. "When the children waited for the school bus in groups, Lindsay stood alone."

Her grandmother said she would sit alone in her room while other children played games outside, and that she was never invited to birthday parties.

"It broke my hear to see her so sad."