IT IS hard to imagine the willowy Sarah Murdoch being vertically challenged, but in her early teens she was pint-sized. Not that she cared. An aspiring ballerina, she had her sights set firmly on a life on stage. But then genetics got in the way. "I used to be the shortest in the class until I was 15 and then I just shot up," says Murdoch, now a graceful 178cm.