In November 1957, Nelson co-starred with Van Johnson in the TV movie "The Pied Piper of Hamelin", which aired as a Thanksgiving Day special. Also in 1957, she was cast in one of the three lead roles in the syndicated sitcom "How to Marry a Millionaire". Based on the 1953 film of the same name, Nelson starred as Greta Hanson, a brainy psychology major who works as an usher on a television game show. The series also starred Barbara Eden and Merry Anders. Nelson opted to leave the series after the first season, and her character was written out.