The alleged rape took place in a private residence in the Romerike district northeast of Oslo.
“It is quite rare that police investigate this type of case,” Guro Holm Hansen, an attorney with the Eastern Police District, told local newspaper Romerikes Blad.
The rape allegedly took place during the 2015 Christmas season. The woman was arrested in September 2016 and has since been held in custody.
The woman's lawyer, Cato Johannessen, said that she completely denies her guilt.
“She maintains that this did not happen,” Johannessen said, adding that no relationship exists between the woman, whose age was not given, and the boy.
The woman is registered as officially living in Romania and had reportedly come to Norway to work.