German federal records indicate Johanna and Evelina emigrated to France in 1939 aboard the "St. Louis".

The record of the annulment of her German nationality gives her last address as Berlin-Charlottenburg, Kaiserdamm 10. Also listed at this address in the 1939 census are:
- Caroline Greve geb. Friede born 18.10.1859 in Bega,
- Ernst Greve born 14.10.1887 in Gadderbaum,
- Anna Greve geb. Wallach born 15.04.1897 in Wiedenbrück,
- Hans-Günther Greve born 28.08.1920 in Bielefeld
as well as other who are not obviously related to the Greve family.

Caroline Greve geb. Friede is likely to be Walter's mother, named in his wife's testimnoial to him as "Lina". Ernst is probably his brother.

A Heinz Ludwig Greve also has the same address recorded on his annulment of German nationality card; like Johanna and Evelina he emigrated to France in 1939 aboard the "St. Louis" and I presume he is the boy shown in the family photo in one of the Yad Vashem testimonials to Evelina.