Survived in hiding in Naarden and Belgium thanks to false identity papers:
https://findingaids.library.upenn.edu/records/UPENN_RBML_PUSP.MS.COLL.1460
Ursula Hertz was born on April 12, 1925, in Germany, the daughter of Walter and Dorothea Hertz. In 1936, when Ursula was eleven and her sister Renée was seven, her Jewish family fled Nazi Germany to live in Aerdenhout, in the Netherlands; however, when the Nazis occupied the Netherlands, the family was forced to move to Naarden where they lived in partial hiding; and later to occupied Belgium, where they also lived in partial hiding. Ursula spent much of that time in Belgium separated from her family, living in complete hiding in the attic of a family acquaintance, placed there by her parents who feared she looked too Jewish.
and
Husband: Walter Hertz
See:
[CLI Part 27] do_fq4XkUYewLGenThDXHmvq Walter Hertz - Dokumente - Talk in the Forum of the Arolsen Archives (arolsen-archives.org)
Daughter: Ursula Hertz
See:
[CLI Part 27] do_jm16ALBESHwkaV76syKfg - Dokumente - Talk in the Forum of the Arolsen Archives (arolsen-archives.org)