Nilson was born in Chicago, Illinois, USA, on 21 August 1908, to parents Christ Rückhardt (1869–1949) and Emma Martha Martin (1872–1966). She had at least two brothers: Fred (1899–1996) and Herbert Otto (1913–1984). Her father was born in Germany.

After graduating from high school, Nilson and her future husband enrolled in a specialized school for physical education that was affiliated with the University of Indiana in Indianapolis. In 1932, she married Herbert B. “Swede” Nilson (1907–1992). The couple had two sons: Robert Martin (1936–2018) and Richard. The couple retired in 1964 to a house built on Stone Lake in Wisconsin.

Nilson kept driving until she she voluntarily gave up her license at the age of 104. She lived independently until she moved to New Hampshire in 2014, when she was 106 years old. She was a dedicated member of the First Lutheran Church of Stone Lake, Wisconsin, for many years until her move to New Hampshire. While residing at the Sunapee Cove Assisted Living facility, she led exercise classes and regularly attended the Kearsarge Community Presbyterian Church in New London, New Hampshire, nearly every Sunday.

Nilson passed away after a short hospitalization in Sunapee, New Hampshire, USA, on 20 November 2019, at the age of 111 years, 91 days. She was survived by two daughters-in-law, six grandchildren, and 13 great-grandchildren.