Show business is easy for Spears. By age 9, she was winning talent shows. At 10 she starred off-Broadway. At 11 it was the Mickey Mouse Club. At 15 she got a record contract. Last year, prepackaged as the girl next door, she sold 11 million copies of her debut album in the U.S., more than any other individual artist. Her 1999 earnings: $15 million.