Lena Grajer was a daughter of Bentzel Grajer and Saartje Hes. She married the warehouse clerk Jacob Roos in Amsterdam on 12 July 1931, a son of Hartog Roos and Leentje Kool. The couple had three children: Bernard Hartog (Bennie), Louis (Loetje) and Josef (Jopie). Lena, her husband Jacob and their three children have been killed in Sobibor on 21 May 1943.
City Archive of Amsterdam, archive card of Bentzel Grajer, Jacob Roos and website www.wiewaswie.nl