[Unlike Carter Cash, who was drafted into the family business at a young age, Ms. Witherspoon was a child model and actress by choice. Still, she knows how Carter Cash must have felt as a kid expected to comport herself like a pint-sized grown-up.] That becomes a big, weird part of a person's personality, ... You have to be very adult, businesslike, professional and then have a colorful and childlike personality when you're performing. It's definitely a formative experience.