Judges convicted Jihane Makhzoumi, 38, of charges including terrorism and child abandonment, highlighting her “informed participation in a criminal enterprise” described as “bloodthirsty”.
“Only a significant sentence could be imposed under these circumstances,” the judges added.
Makhzoumi left France with her partner Eddy Leroux – another IS convert believed to have been killed in Syria – her three young children and a fourth child, the daughter of Leroux.
She was arrested at a Paris airport when she returned along with her three children in 2016 – Leroux's daughter having apparently been left behind in Syria.
The prosecutor had told the court Makhzoumi had a personality of “appalling egocentrism” and had “at no time shown a capacity for empathy”.
“This departure to Syria is absolutely not an accident, it is the result of years of radicalisation,” said the prosecutor.
“The lives of their own children do not matter that much, in comparison to their project.”
Makhzoumi appeared visibly shocked when the verdict was announced and her lawyers labelled the sentence “totally disproportionate” and said they would appeal.