The sister of a Pakistani prisoner described as the "poster girl" for Islamic jihad has urged ISIS hostage-takers to let their captives go.

Speaking exclusively to CNN from her home in Karachi, Pakistan, the sister of Dr. Aaifa Siddiqui said the jailed neuroscientist's family wanted "no violence in Aafia's name."

"I'm Aafia's sister. We're Aafia's family. And we speak on her behalf as well. We want no violence in Aafia's name. Our whole struggle has been one that is dignified that is peaceful that is legal," Fowzia Siddiqui said.

A jury in New York convicted Aafia Siddiqui on seven charges, including attempted murder and armed assault on U.S. officers, in 2010. No one was wounded in the incident. She is serving her 86-year sentence at a facility in Texas.

At the time of the 2008 shooting, Siddiqui was in police custody after being arrested outside the Ghazni governor's compound in Afghanistan. She was said to be acting suspiciously and found to be carrying "numerous documents describing the creation of explosives, chemical weapons, and other weapons involving biological material and radiological agents," according to court documents.

The papers included descriptions of various U.S. landmarks and military assets, excerpts from the "Anarchist's Arsenal," and a number of chemical substances in bottles and glass jars, the documents said.

(CNN)