Esperance Nanette Leefsma (named Erna) was a daughter of Louis Leefsma (deceased in 1932) and Rozette Elzas, (who survived the Holocaust). She married Herbert Loeb in Amsterdam on 3 Juni 1942, a son of Ernst Loeb and Jenny Rose, who both have been killed in the Shoah.

Erna had two other sisters, Eliza Nanette and Regina Hanna, and a brother Benjamin. They too have been killed in the Shoah.

City Archive of Amsterdam, archive card of Rozette Elzas, Herbert Loeb and Esperance Nanette Leefsma.