Alida Mathilda de Jong was a daughter of Mozes de Jong and Mietje Pach. She was the unmarried mother of Mirjam de Jong, who has survived the Holocaust.
Alida had another sister Henriette and three brothers, Samson, William and Jozeph, who also have been killed during the Holocaust.
City Archive of Amsterdam, archive of Mozes de Jong and Alida Mathilda de Jong.