She made a name for herself acting in television shows in the 1950s and 1960s and as a film co-star with Cary Grant, Elvis Presley, John Wayne, and Jerry Lewis.

[1] O'Brien's singing abilities came to the attention of entertainer and Country Music Hall of Fame member Cliffie Stone, who hired her as a regular performer on his television show Hometown Jamboree before her high school graduation.

O'Brien was cast as survivor Susanna Dickinson in John Wayne's 1960 epic feature film retelling of battle of The Alamo.

[3][4] That same year, O'Brien performed as a soloist for composer Buddy Bregman at the Moulin Rouge night club in Los Angeles.

[6] Along with Sheree North, Sabrina, and Sue Carson, O'Brien appeared in Playgirls in 1961 at the Riverside Hotel in Reno, Nevada.