Nehemias (Nathan) de Rooy was a son of Abraham de Rooy and Kaatje Cartoef. He married in Amsterdam to Alida Sjouwerman, who has survived the Holocaust//.
City Archive of Amsterdam, archive card of Abraham de Rooy and Memorbook of Mauthausen, page 133.
For a biographical note see: H.E. Dominicus, Mauthausen. Een gedenkboek (2e herziene en uitgebreide druk; Amsterdam 1999) 133.