Who is Kay Fischer from The Blue Afternoon: A Novel and what is their importance?

Kay Fischer, putatively born Kay Carriscant, is the daughter of Annaliese Leys and the step-daughter of Rudolf Fischer. Kay was born January 9, 1904, in German New Guinea and then traveled to Long Beach when she was only a few years old. Kay describes herself as 5'6" tall with dull brown hair and bright brown eyes.