According to the newspaper, the woman left her hometown in 2013 to join the terrorist sect.
After the fall of IS in 2019, she was held in the camps al-Hol and Camp Roj, before she was returned to Sweden in October last year by Swedish authorities.
She had two small children with her.
Together with two other Swedish citizens who were also brought home, she was arrested on arrival at Arlanda, and criminal investigations were initiated against all three.
The woman from Gothenburg was suspected of crimes against humanity, war crimes and violations of international law.
After almost six months, it is now announced that the preliminary investigations will be closed due to a lack of concrete evidence.
The two children were taken care of by the social services on arrival in Sweden.
The Administrative Court later ruled that the children should be provided with compulsory care within the framework of LVU.
According to the children's public counsel, they showed "severe trauma syndrome".
The woman herself has stated that she followed her boyfriends, who were IS supporters, without participating in any criminal activity.