Linda Wenzel, 16, ran away from home in Germany a year ago after her parents separated and her mother Katharina began a new relationship with a caretaker at a local school.
The teenager, described as 'a brilliant student', fled the country using her mother's passport and flew from Berlin to Turkey before making her way to Syria.
She was captured in the ruins of war-torn Mosul, Iraq's second-largest city, with 20 members of the terror group's fearsome all-female police force, some of whom were wearing suicide vests.
Today her neighbours in the village of Pulsnitz, near Dreseden, south-east Germany, told of their shock and anger that the promising youngster left home to join the extremist group.
One former neighbour in the town of Gruenestrasse, where she lived with her parents before they split up last year, said: 'What a b***h for putting her parents through this.
'What sort of a person gives themselves over to a group killing her own people in Germany? I hope a jail cell awaits her when she returns, not yellow ribbons.'