Margarete Theisen was born in 1857 in Baden, Germany. After immigrating to the United States, she settled in Ohio, where she married Lawrence P. Fisher in 1876.

The couple had eleven children, among whom were seven sons: Frederick J., Charles T., Lawrence P., William A., Edward F., Alfred J., and Howard A. Fisher. Together, these sons founded the Fisher Body Corporation.

In the 1920s, Margaret T. Fisher lived at 101 Longfellow in Boston-Edison, along with four of the Fisher Brothers, following her husband's passing.