[2] By the age of 18, she passed her teacher's exam in Stettin, Pomerania (now Szczecin, Poland) but felt inadequate and experienced "the burning desire to improve my intellectual culture".

This role was fulfilled by the Unitarian Narborough Road Free Christian Church in Leicester which decided to rise above the convention and invited her unanimously – in competition with several male candidates – to the pulpit.

[6] In Des Moines, she served as an interim pastor in the absence of Mary Safford, fulfilling that minister's role as chaplain to the Iowa General Assembly.

[6] Shortly after the start of the First World War in August 1914, Petzold had to return to Germany since her application to obtain British citizenship had lapsed and emigration to the USA was not possible.

[1][2] At the end of the First World War, Petzold joined the Social Democratic Party of Germany and became a city councillor in Königsberg, West Prussia (now Kaliningrad, Russia).

[1] She was socially active in the Monistenbund (Union of monists, founded in Jena in 1906 by the natural scientist Ernst Haeckel) and later as a member of the National Socialist People's Welfare.

[1] In 1941, she qualified through the writing of a habilitation for the possibility of gaining a professorship at the University of Kiel in Germanics – being the first woman to achieve this in Germany.