Sientje de Leeuw, born in 1884 in Steenwijk, was a daughter of the butcher Jacob Israel de Leeuw and Judith Rosenbach. 21 June 1911 she married in Steenwijk the travelling salesman in paper Elkan Kosman, a son of the travelling saesman Izak Kosman and Rosetta Rosenbach. The couple had two daughters, namely Julia Roza in 1912 and Roza in 1914.
Their daughter Julia Roza was psychologist and moved to Utrecht in 1933. But in Rotterdam she married 30 June 1938 the mechanical engineer Johannes Solleveld from Rotterdam. She surived the Holocaust. Her sister Roza was an assistant pharmacologist. She left Rotterdam in 1937 for Batavia (Dutch East Indies) and returned to Rotterdam after the war in 1946.
Elkan Kosman resided since 1896 at 1st Middellandstraat 77b, where Sientje the Leeuw came living in after her marriage to Elkan in 1911. Ten years later, on 3 August 1921 they moved to Claes de Vrieselaan 43. After the passing of his wife in 1940 and during the registration of the Jewish population of Rotterdam by the Jewish Council in 1941, Elkan still lived at that address. But Elkan Kosman has survived the Shoah and his registration card showed his address after the war: per 19 Feberuary 1948 he lived at Aelbrechtstraat 30a in Rotterdam.
Sientje Kosman-de Leeuw however has been hospitalized on 27 January 1940 in the Jewish Hospital at Schietbaanlaan 42, where she passed away 11 October 1940. The funeral records at the Jewish cemetery Toepad in Rotterdam reveal that Sientje de Leeuw was buried there.
City Archive of Rotterdam, family registration card of Elkan Kosman; website wiewaswie.nl, marriage Kosman/de Leeuw and the file cabinet of the Jewish Council, registration card of Elkan Kosman.