Nathalie Haddadi, 43, insisted she did not know how her son Belabbas Bounaga spent the money she wired to him and said the conviction was a "double punishment" for a grieving mum.
"I have trouble understanding how they can accuse me of financing terrorism," Haddadi told reporters before hearing the verdict.
"I helped my son," she said, while insisting she had never sent money to Syria.
The judge said Haddadi had known "perfectly well" that her son was using the money to travel to Syria and that the sentence was in keeping with "the gravity" of the acts.
Two-year sentences can be eased in France to a non-custodial punishment.
Haddadi, a marketing adviser who lives in the eastern French region of Alsace, was convicted for transferring 2,800 euros ($3,300) to her son while he was in Malaysia, on a circuitous route to Syria.
She also paid for her son -- who had been barred from leaving France -- to travel to Algeria to be with his father, who is Algerian, who she thought could "save" the youth.
Haddadi, a non-practising Muslim, said she had informed the authorities that her son had been radicalised while in jail for drug offences.
Haddadi was also accused of hiding her son's passport from the authorities.
Prosecutors said Bounaga travelled from Malaysia to Syria where he joined the Islamic State group.
In August 2016, Haddadi received a phone call informing her of her son's death at age 21.
Haddadi's lawyer Herve Denis said she would appeal the verdict, to avoid it becoming a precedent for the 2,000 French parents whose children had travelled to Syria to wage jihad.
Convicting a "tearful mother...is not harsh, it's nasty," he said.