From first daughter to U.S. ambassador. Caroline Kennedy, the only living child of President John F. Kennedy’s, is expected to be named U.S. ambassador to Japan. The 55-year-old Kennedy daughter is a lawyer and author of 10 books. She played a crucial part in President Obama’s reelection campaign, making several appearances on his behalf in swing state New Hampshire and echoing the attack that Mitt Romney was the wrong candidate for women. She will replace John Roos, who has served as ambassador since 2009, and succeed other luminaries like Walter Mondale, Howard Baker, and Tom Schieffer.