MARY CROSBY — Kristin Shepard

THEN: The daughter of crooner Bing, Mary played Sue Ellen’s scheming sister. After spying on JR’s business partners for a reward, Kristin — also JR’s mistress — felt betrayed when she got nothing and shot him.

NOW: Mary, 58, says playing a murderess was a poisoned chalice. The mother-of-two had roles in Hollywood Wives, Beverly Hills 90210 and the film Star Trek, but says: ‘I made that classic mistake — thinking I could afford to wait around for more “arty” roles,’ adding, ‘that’s not going to happen just from starring in Dallas.’