Mary Eidt Ratz was born to Christine Eidt and Henry Ratz in Gads Hill, Ontario on December 14, 1856. Mary was one of 13 children born to Christine Eidt and Henry Ratz.

In March 1877, Mary married Jacob Kaufman, who at the time worked as a sawyer in her father's saw mill. Together, Mary and Jacob moved to Berlin (now Kitchener), Ontario. Mary and Jacob had seven children. Only two of their sons and two of their daughters reached adulthood; Emma Ratz Kaufman, Alvin Ratz Kaufman, Milton Ratz Kaufman, and Edna Louise Kaufman.

Mary was a member of the Zion Evangelical Church throughout her life and led the Zion's women's society. Mary was also actively involved in many civic and community initiatives. She was the president of the local Children's Aid Society and the Young Women's Christian Association (YWCA) and a member of the National Council of Women of Canada, the Women’s Hospital Aid Association of Ontario, and the Woman’s Christian Temperance Union. Mary was also known to support the Kitchener-Waterloo Orphanage and the Kitchener-Waterloo Hospital.

Mary died on December 24, 1943.