In her research, she focused on the history and theology of Eastern orthodox churches, with studies not only in Breslau and Hamburg but also in Prague and the Soviet Union where she lived when the Nazis came to power.
She attended a private school first in Kiel and later, after her father had accepted a call from the Silesian Friedrich Wilhelm University, in Breslau, where she achieved the Abitur as an external student in 1920.
She began working as a research assistant in the Publikationsstelle Berlin-Dahlem [de] of the Prussian Privy State Archives in Berlin in 1935.
[1] Schaeder became a member of the Confessing Church in 1934, and from 1935 also worked actively in the Jesus-Christus-Kirche Dahlem [de], which was ministered by Martin Niemöller.
She studied at the Kirchliche Hochschule für reformatorische Theologie which Niemöller had initiated in 1935, and which was run illegally after being banned immediately.