When Koster was born on 9 March 1880, in Hoogeveen, Drenthe, Netherlands, her father, Jan Jans Koster, was 44 and her mother, Hendrikje Roelofs Koster, was 41. She died on 9 March 1880, in her hometown, at the age of 0.
Dutch; North German (also Köster): originally a status name for a supervisor of the ecclesiastical garments of a church, later for a sexton, Middle Dutch coster(e), Middle Low German koster (from Latin costurarius). See also German Kuster , compare Koester .
North German (Köster): occupational name or status name for a tenant on a small farm, from Middle Low German koster, from kossater ‘cottager’. Compare Koester .
South German: occupational name for a wine taster, from kosten ‘to taste’.