The daughter of Abraham John (1840-1924) and Anna Fast (1841-1898) Harder, Aganetha "Agnes" Harder was born 24 January 1884 at Alexanderwohl in the Molotschna Colony, Russia. Her father and stepmother brought her from Russia to attend Bethel College, North Newton, KS. She graduated from Bethel Academy in 1904. Planning to be a deaconess, she took nurse's training in Cincinnati with Martha Richert Penner. She married Peter Jacob Wiens on 14 February 1906 at West Swamp Mennonite Church, Quakertown, PA.

As a General Conference Mennonite missionary in Mauhadih and Basna (later known as Jagdeeshpur), India, 1906-1915, 1917-1925, 1927-1937, she supervised educational, medical, and nutritional aspects of mission boarding schools, inspecting students every morning. Because of the caste system, whole groups came for baptism into the Christian faith, as many as 90 at one time. The children of Agnes and Peter Wiens were Ferdinand Jacob (1907-1980), Rudolf Peter (1909-1972), Agnes Mieka Willis Bailey (1913-), Martha Elizabeth Koehn (1919-), and Frieda Esther Epp Krehbiel (1919-). Agnes Wiens died 17 August 1951.