This undated file image posted on a militant Web site on Jan. 14 shows Islamic State fighters marching in Raqqa, Syria. (AP)

In February, 18-year old Aicha traveled from the Netherlands to Syria to marry a Dutch-Turkish Islamic State militant named Omar Yilmaz. She was born under the name Sterlina, but she changed her name after she became increasingly radicalized. Her love affair with the jihadist would end, as many relationships do. But what happened afterward is far more remarkable, according to several news reports: Aicha's mother tried to cross the border into Syria to rescue her daughter. She failed, and then tried again.

After being separated from her daughter for nine months, her mother, Monique, succeeded in rescuing her daughter from the Syrian city of Raqqa two weeks ago, according to her lawyer, who told the Telegraph that she had worn a burqa to hide her identity. A Dutch public prosecutor provided a slightly different account to news agency AFP, saying the mother and daughter met close to the Turkish-Syrian border.

“She rang me and said, 'Take me home.’ But she could not leave Raqqa without help," her mother told the British paper. Dutch police officials, the mayor of Maastricht as well as the Dutch Foreign Affairs Ministry had previously discouraged her mother from making the trip.

But Aicha's story did not end there. Shortly after returning to the Dutch city of Maastricht, she was arrested on suspicions of crimes threatening state security.

Experts say Aicha is not the only foreign woman who has fallen in love with or married a jihadist fighter in Syria. Now, their cases are posing a new question for prosecutors: Are women who join the Islamic State to marry militants victims, or are they criminals themselves?

In a Dutch TV interview in September, Aicha's mother described how her daughter had changed within a short period of time from an enthusiastic Dutch teenager to a radical Muslim. "She saw [Yilmaz] as a sort of Robin Hood," her mother said.

According to Mia Bloom, a professor at the Center for Terrorism and Security Studies at the University of Massachusetts Lowell and one of the world’s few researchers specialized on female terrorists, as many as 200 young foreign women were living among the Islamic State as of October, although few cases have been verified. The Guardian newspaper recently reported that U.S. law enforcement authorities were investigating several cases of women who appear to have been recruited by the Islamic State in the United States. 

Yilmaz, who had served in the Dutch army, joined the Islamic State after unsuccessfully applying for a special forces position several years ago. After watching a TV interview with him, Aicha became more and more obsessed with the militant, according to the Telegraph.

Aicha managed to reach Syria mainly by train in February, Canada's Globe and Mail reported, despite the fact that her passport had been taken away as a precautionary measure after friends had grown concerned.

So far, it is uncertain how exactly Aicha was involved in Islamic State activities in Raqqa and whether she participated in the fighting. In order to control and search women in the territory held be the militants, the Islamic State has established a female brigade that works alongside male fighters -- for example, at checkpoints. Perhaps more important, women are crucial to the recruitment process of the Islamic State. “Their presence is supposed to awake shame among male supporters of the group who see that women -- which are considered inferior -- are ‘courageous’ enough to join the jihad,” Bloom explained to WorldViews.

The arrest of Aicha, now 19, after her return to the Netherlands has also highlighted another ongoing debate: What should happen to returning jihadists more generally? Some European countries have taken tougher stances than others.

The Netherlands, for instance, has opted for arresting returning fighters and has sentenced several militants in absentia. Britain is expected to publish a new counterterrorism bill at the end of the month that would restrict entry of former Islamic State members. Some parliamentarians argued that such a law was necessary because it is often hard to prove an individual's involvement in criminal activities in Syria. The Danish city of Aarhus, however, has chosen a radically different strategy by offering career advice and counseling.

A court decided on Tuesday that Aicha would be provisionally released from custody. But she still faces up to 30 years in prison if evidence proves that she fought alongside Islamic State militants.