Photo: George Burns/Harpo Studios

Like many women who have had long careers in the public eye—beauty icons like Bo Derek and Cybill Shepherd—Diana has had to age in the spotlight.

"How are you handling that?" Oprah asks. "You look as glamorous as ever!"

"I really would like to age gracefully," Diana says. "And I feel that the vitality or your energy of who you are comes from inside. ... [Besides] I like my lines."