In the mid to late 1980s, beautiful Rebecca Schaeffer – with her big brown eyes, curly brunette mane and megawatt smile – was an ambitious and promising young actress making her way in Hollywood. At the age of 19, she won the breakthrough role of her short career, starring in the television sitcom “My Sister Sam” (CBS 1986-88) as Pam Dawber’s adorable, smart-mouthed younger sister. Even after the show was cancelled two years later, it seemed that the rising young starlet would have her pick of roles to look forward to. On the final day of her life, she was prepping to audition for none other