Nova Scotia Supreme Court Justice Peter Rosinski described Souvannarath as an unrepentant threat to society.
He said she expressed no remorse for her plot to senselessly kill people.
Souvannarath declined to address the court prior to her sentencing, according to reports.
Rosinski said an anonymous tip and swift police action thwarted the planned attack on unsuspecting shoppers.
Former high school classmates described Souvannarath who graduated in 2014 with a bachelor of arts in English and creative writing from Coe College, a liberal arts college in Cedar Rapids, Iowa, said she displayed a “creepy” interest in Nazis, while in high school. She was also credited with such as comments like “stupid people deserved to die.”
Another former classmate said: “She was in my writing club and her writing was so violent and gory and visceral,” she said.
Third accomplice, Randall Steven Shepherd leaves court in Halifax, Nova Scotia, Canada, March 6, 2015. He is serving 10 years for his role in the plot
At sentencing Justice Peter Rosinski , said he followed principles that apply to terrorism in issuing the sentence. His aim was to “send a clear message” to would-be murderers, adding that “they will pay a heavy price.”
The judge gave Souvannarath credit for time served in custody, making her eligible for parole in seven years.
then 23-year-old Souvannarath had boarded a Nova Scotia-bound plane in Chicago when police received the tip that led to her arrest. Her Canadian co-conspirator, James Gamble, 19, killed himself as police surrounded his Halifax-area home.
The 20-year-old Randall Steven Shepherd, also from Geneva, Ill., a third accomplice, was also arrested at the airport and was sentenced to 10 years in jail for being a “cheerleader” of the plot.
The judge entered new letters into evidence from Souvannarath’s parents and grandparents, who were present in court.
Souvannarath and Gamble were both unemployed and living with their parents when they hatched the plot.
Their online correspondence shows the pair held the Columbine High School killers in high esteem. They divulged their shared admiration for mass shootings as they conspired to kill as many people as possible at the Halifax Shopping Center food court.