When Bertha Wilhelmine Zobel was born in February 1872, in Neudorf, Graudenz, West Prussia, Prussia, Germany, her father, George Christian Kruger, was 39 and her mother, Anna Dorathea Wichmann, was 27. She married Gottfried Friedrich Maass on 10 November 1887, in Sauk City, Sauk, Wisconsin, United States. She lived in Washington, Sauk, Wisconsin, United States in 1900 and Reedsburg, Sauk, Wisconsin, United States in 1920. She died on 9 December 1963, in Sauk, Wisconsin, United States, at the age of 91.