Josephina Roos was a daughter of Isaac Roos and his second wife Elisabeth Ossedrijver and was born on 18 August 1882 in Rotterdam. Josephina was the youngest of the 13 children of Isaac Roos, who was first married to Sara Blok, a daughter of David Blok and Esther Herts, with whom he had 6 children. Sara Blok died on 6 February 1870 in Rotterdam, after which Isaac Roos remarried on 7 September of t…