Providing employment, she established a manufacturing center where women produced textile goods and men learned agricultural skills.

[2] When her mother died in 1890, she moved to Copenhagen and began working with prostitutes for the Young Women's Christian Association (Danish: Kristelig Forening for Unge Kvinder.

[1] In 1898, Nielsen arrived in China and was assigned to work at the Missionary Church in Dandong, Liaoning Province providing nursing care at the West Street Clinic.

[3] Because of an epidemic at that time, she was sent to Dagushan (Chinese: 大孤山镇), a town lying to the southwest of Dandong, where she saw up to 100 patients per day.

[1] The school taught girls embroidery skills and then sold the handicrafts produced abroad to fund the institution,[5] as well as providing them with classes in reading, hygiene and religion.

[3] Nielsen founded the Chongzheng Girls' Primary School (Chinese: 崇正女子小学) in 1908 and four years later she opened a center for homeless women.

[2] Using her salary, she paid each worker seven dollars a month in addition to sharing with them the crop yields and livestock, as well as providing free schooling for their children.

[1] In 1942, during the Japanese invasion of Manchuria, they overtook the school, changing the name to Dagushan National University of Higher Education.

[2] When the communist administrators took over the village, they seized the church school, closed the factory and poor relief agency, and allocated the land and houses to other workers.

[3] In 1949, the new regime promised religious freedom and the church building, four cows, an orchard and a pond were returned to Nielsen.

[2][3] She tried to reorganize the community and revive the church, but her hopes were short-lived when another wave of denunciations was prompted by the government and she was branded as an imperialist.