Biography 7 April 2016 About Sonja Kool By: Redactie Joods Monument Sonja Kool was a daughter of Aaltje Kool. She had another sister Elly and six half-brothers and half-sisters: Jacob, Elias, Rebecca, Joseph, Elisabeth and Asser Aandagt. Stadsarchief Amsterdam, archiefkaart Isaac Aandagt.