According to the media reports, Rasmiya Awad, 65, was detained on Monday evening in the city of Azaz, the province of Aleppo in northern Syria, on suspicion of having links to an extremist group.
The woman was accompanied by her husband, her daughter-in-law and five children.
Abu Bakr al-Baghdadi blew himself along with two of his children, in a US raid at a compound in Syria's town of Idlib.
The images released by the Pentagon show Baghdadi's compound before and after United States military operation.
The adults taken into custody by the Turks are being interrogated, the official said, speaking on condition of anonymity In line with government protocol.
The banned terror outfit confirmed the death of its leader Abu Bakr al-Baghdadi in an audio statement.
He added that the arrest could be "an intelligence gold mine".
"What she knows about [ISIS] can significantly expand our understanding of the group and help us catch more bad guys", they said. It also poured cold water on Trump's claims that Russian forces had opened up the airspace under its control in Syria to American warplanes, so that they could reach al-Baghdadi's compound.
The raid was a major blow to ISIS, which has lost territories it held in Syria and Iraq in a series of military defeats by the US-led coalition and Syrian and Iraqi allies.
The reclusive leader al Baghdadi was known to be close to one of his brothers, known by his nom de guerre Abu Hamza.
Trump added that Baghdadi committed suicide by detonating a suicide vest inside a tunnel following a two-hour-long gunfight with USA forces.
"They arrested her, her husband, her daughter-in law, and her five grandchildren".
Trump initially promised to release a video of the raid, but the Pentagon later said that it had disposed of al-Baghdadi's remains at sea and have no plans to share any videos or photos.
Turkey considers these Kurdish-led forces to be terrorists, but the same fighters had also made up the core of the US -backed force that battled the Islamic State group.
Abu Ibrahim al-Hashemi al-Qurashi has since been named as IS's new leader and "caliph".