Olympic Medalists: 1 bronze, 1 gold, 1 silver
(gold) Nida Senff (middle name Jacoba)   1936   swimming - 100 m backstroke  
(bronze) Tineke Lagerberg (middle name Jacoba)   1960   swimming - 400 m freestyle  
(silver) Coby van Baalen (a.k.a. Jacoba)   2000   equestrian