NICE, France—Valérie Aubry-Dumont got the news in a WhatsApp message from deep inside Islamic State territory. “Mom, you’re going to be a grandmother,” wrote her teenage daughter, Cléa.
When Ms. Aubry-Dumont last saw her daughter, Cléa was a 16-year-old girl attending Catholic school in a Paris suburb. After a breakup, Cléa met a young man online and within months the couple fled France to live in a stretch of northern Syria ruled by Islamic State.
“I wish Cléa never had children,” Ms. Aubry-Dumont, a child-care worker, says now that her grandson has been born. Her daughter talks some days of returning to France, Ms. Aubry-Dumont said, but is afraid of losing her baby if she tries to leave. “She is trapped.”
In France, the West’s biggest supplier of foreign fighters in Syria, the loss of sons, daughters and grandchildren to Islamic State has been a slow-motion tragedy. For some French families, the Paris attacks, while deepening the wedge between militants and the West, were a painful reminder of their ties to the enemy.
The French wife of Foued Mohamed-Aggad—who along with two others killed 90 people in Paris’s Bataclan concert hall on Nov. 13—is living in Islamic State territory and ready to give birth “any day now,” said Françoise Cotta, a lawyer Mr. Mohamed-Aggad’s mother approached in an attempt to bring the child back to France.