Katherine Eunice Schwarzenegger Pratt (née Schwarzenegger; born December 13, 1989) is an American author. == Early life and family == Schwarzenegger is the eldest child of Austrian-born American bodybuilder-turned actor and politician, Arnold Schwarzenegger, and American journalist and author, Maria Shriver. She is of Irish and German descent through her maternal grandparents, Eunice and Sargent Shriver. She has a younger sister, Christina, two younger brothers, Patrick and Christopher, and a …