Adriënne de Grauw’s youngest daughter was Lydia de Ridder (1852-1921). She was married to Louis Willkomm who owned the dancing establishment: “Pschorr”, a well-known establishment on De Blaak in Rotterdam. Above the establishment, the Willkomm family lived very comfortably in a flat with a beautiful roof garden. Pschorr also had a bowling club. Grandfather Georg Hahn was a member of this bowling club and that is how he and Jo Aarsse met at Uncle and Aunt Willkomm’s place.