She worked under the direction of F.S. Seyler's husband Abel Seyler at the Mannheim National Theatre until 1781, when a quarrel between her and the director led to his retirement. She was described as a "scheming" character; although Friederike Sophie Seyler was also regarded as a very difficult person to work with.

She was married to Giovanni Federico (also known as Johann Friedrich) Toscani, a noted tenor born in Warsaw in the 1750s to an Italian family. Her husband