A French woman who escaped the Islamic State (Isis)-held city of Raqqa after joining the group with her four-year-old son has spoken about her ordeal in the city, describing it as "a journey into hell". "I have felt so guilty. I have asked myself how I can live with what I have done, taking my son to Syria," she said.

In an article published in The Observer on 10 January, Sophie Kasiki (not her real name) told of how she had gone to Raqqa via Turkey after being manipulated by fighters in the city. When she arrived there, she found that the paradise she had been told of did not exist: she was not allowed to go out alone, was forced to completely cover herself and had her passport taken away.

Kasiki was born into a staunchly Catholic family and later converted to Islam without telling her atheist husband. Three men she met through her new faith left for Syria and were the ones who convinced her to join. She said: "I thought I was in control of the situation, but I realise now they were probably trained to recruit people like me... they played on my weaknesses. They knew I was an orphan and I had converted to Islam, they knew I was insecure."

In Raqqa, she was made to work in the maternity hospital where she found squalid conditions and staff indifferent to their patients. When she said she wanted to leave and return to her family in France, she was told she would be stoned and killed if she did. When one of the men tried to take her son to pray at the mosque, she said "keep your hands off my boy", which the man responded to by punching her.

While being made to stay in a guesthouse, Kasiki found an open door and escaped with her son. A local family risked their lives by taking her in, and she managed to make contact with opposition fighters. She made her way to the Turkish border on the back of a motorbike.

"I have gone back over everything and asked myself, how did this happen, how could I have done this? Yes, I was naive, confused, fragile, vulnerable even, but how were these ordinary, not particularly smart boys intelligent enough to brainwash me? It is a question I still ask myself," she said.

Once back in Paris, Kasiki was interrogated by French intelligence and kept in jail for two months without any contact with her family. She is still facing possible child-kidnapping charges.