Barbara was a former roommate of Carousel (1956) co-star Shirley Jones in New York when they both were starting out. When Jones married singer/actor Jack Cassidy, Barbara sang "When I Marry Mr. Snow" at the wedding.
Daughter-in-law of Johnny Williams.
Her son, Joseph Williams, was the lead singer of Toto from 1986-1989 and the singing voice of the Adult Simba in Disney's The Lion King (1994).
Her son, Mark Towner Williams is a recording artist/music producer. He has recorded several CDs under the name "Lionel's Dad". He is also the drummer/music director for the music group Air Supply.
Husband John Williams composed "Treesong" between the years 1974 and 1976, a concerto for violin in memory of his late wife.
She and husband John Williams initially met in high school. They met later again as adults and this time fell in love.