According to the Gothenburg District Court, the couple “in agreement and as a team” used threats and violence to compel the two 17-year-old girls to have sex with them, the Metro newspaper reports.
The 28-year-old woman, in addition to participating in the sex attack itself, was also found to have betrayed the trust placed in her by one of the girls.
The girl told the court that she had viewed the woman like an older sister.
While the couple admits to having sex with the girls, they claim that the teens were willing participants in the prolonged assault.
The woman and her 29-year-old boyfriend each received prison sentences of 3.5 years for the crime.
According to Elisabeth Kwarnmark, a psychologist for sexual criminals with the Swedish Prison and Probation Service (Kriminalvården), only four women have been convicted of rape in Sweden in the last decade.
In most cases, she added, the woman is convicted along with a male accomplice.