After rejoining her parents and her two younger brothers, Ernest and Fritz, she attended the Osnabrück and Hildesheim high schools and, later, the Hanover Business Institute.

After the premature death of her father, victim of cancer, in the late 1920s, the family began to suffer severe financial difficulties.

Threatened by the Gestapo with being sent to a concentration camp, following hours of interrogation, she made the decision with her mother to leave Germany, arriving by boat in Portugal in 1934, and settling in the city of Porto, where her brother Fritz was already living.

In 1949, she published her first book, O Mundo em que vivi (The world I lived in), which told of her childhood, adolescence and youth, until the time she left Germany.

In this sense, Losa's novels explore before, during and after the Holocaust, examining different actors who were involved in the event, such as the victims, the perpetrators, the bystanders and the resisters.