A Milan court sentenced Maria Giulia Sergio, who now goes by the name 'Fatima', along with her husband, Albanian national Aldo Kobuzi, and three other family members.
Sergio, 29, received a nine-year sentence, according to Il Corriere, which was what the prosecutors had requested.
The ruling is the first in Italy dealing with foreign fighters in absentia. Sergio is thought to still be in Syria, where she joined the terror group Isis two years ago.
Sergio's mother- and sister-in-law were also sentenced to eight years each.
Her father, Sergio Sergio, was the only member of the group not to have left Italy. He received a four-year sentence for "organizing and financing a journey for terrorist purposes".
The couple's relatives were arrested in June last year as part of Italy's anti-terrorism sweep, after having sold their furniture and applied for passports.
A former student at the University of Milan, Sergio gave a chilling interview to Il Corriere, in which she described the Islamic State - where women have been raped and forced into sexual slavery - as the “perfect country", where people respect human rights.
In the wake of the terrorist attacks in Paris in 2015, ex-Interior Minister Angelino Alfano said fresh legislation would target "foreign fighters" seeking to travel from or through Italy en route to joining Islamic militants.
The new law gave the Italian government power to confiscate suspects' passports.