At the age of 19, she passed the exam as a primary school teacher and studied economics with a focus on social policy at the University the of Berlin.

Following her dismissal from Pestalozzi, Sommer found work with various Catholic agencies who helped “non-Aryan” Christians emigrate from the Third Reich.

In 1935, on Sommer took up a position at the Episcopal Diocesan Authority in Berlin, counseling victims of racial persecution with the Catholic aid agency, Caritas Emergency Relief.

From 1939 she became increasingly active in the Welfare Office of the Berlin Diocesan Authority ("Hilfswerk"), and in 1941 she became managing director under the Cathedral Provost Bernhard Lichtenberg.

[1] Lichtenberg was a noted anti-Nazi resistor, who was under the watch of the Gestapo for his courageous support of prisoners and Jews, and who was arrested in 1941 and died en route to Dachau in 1943.

Monsignor Horst Roth described Margarete Sommer as a "wise, resolute woman", who found hiding places for two men in the crypt of the Sacred Heart Church.

[7] While working for the Welfare Office of the Berlin Diocesan Authority, Sommer coordinated Catholic aid for victims of racial persecution, giving them spiritual comfort, food, clothing, and money.

[1] In 1943 Sommer and Preysing drafted a statement for the German Bishops which would have actually rebuked Hitler for human rights abuses and mass murder.

The draft began, "With deepest sorrow--yes even with holy indignation--have we German bishops learned of the deportation of non-Aryans in a manner that is scornful of all human rights.

The end of the draft chided Hitler on the very issue of genocide: "We would not want to omit to say that meeting these previously mentioned stipulations would be the most certain way to deflate the crescendo of rumors regarding the mass death of the deported non-Aryans."

She aided many to escape to West Berlin until she was forced to literally leave the newly founded GDR under cover of darkness in 1950.