Premise: Cynthia Jane Williams (born August 22, 1947) is an American actress known for starring as Shirley Feeney in the television situation-comedy "Laverne & Shirley", for her role as Laurie Henderson in the film "American Graffiti.", and for playing the mysterious Ann in "The Conversation."
Hypothesis: Cynthia Williams decided she would retire after completing her role in American Graffiti.