Beck has starred in a number of Australian theatre productions. In 1992 she performed the title role in "Young Judy" – a one-woman show on the early life of Judy Garland – written by her father, John. She appeared in the Australian stage productions of Disney's "Beauty and the Beast" (1995–1996) as Belle opposite Hugh Jackman, (the cast recording of which won an ARIA Music Award for best cast album of 1996) "Les Misérables" as Fantine (1997–98), "The Sound of Music" (August 2000 to February 2001), taking over from Lisa McCune as Maria for the Perth and Adelaide productions), "Cabaret" as Sally Bowles, "Singing in the Rain" as Kathy Selden. In 2006, Beck (as Gladys Hotchkiss) appeared alongside her husband Ian Stenlake (as Sid Sorokin) in a stage production of "The Pajama Game" at Melbourne's State Theatre.