Jiska Manuskowski was was the second child of Maurits Eduard Manuskowski and Milly Koekoek. Jiska was born in the transit camp Westerbork. Since the father was unable to register the birth 'because of absence', it was registered by the gynaecologist Herman Heymans.
Record of birth certificates of the Westerbork municipality, currently at the archives of Gemeente Midden-Drenthe in Beilen