Related Information for Lennon Sisters The Lennon Sisters were a singing group consisting of four siblings: Dianne, Peggy, Kathy, and Janet. They were all born in Los Angeles, California.These singers debuted on The Lawrence Welk Show in 1955 after their school classmate, Larry Welk, son of Lawrence Welk, brought them to the attention of his father. They were a mainstay on the show until they left to start a career of their own in 1968. The quartet was only three members from 1960 to 1964; oldest sister Dianne got married, lef.. read more