[2] Helm began performing on Broadway in the 1940s as she danced in High Kickers (1941),[3]: 85  Lady in the Dark (1943),[3]: 153  and Mexican Hayride (1944).

[2] Her 1958 title role in Shirley Temple's Storybook's presentation of "The Sleeping Beauty" was the subject of an article in Life magazine.

Helm was cast as Linda Moon in the 1960 episode "A Thief or Two" on CBS's anthology series, The DuPont Show with June Allyson, with co-star Lew Ayres.

She also played Glamis Barlow, the title character, in the Perry Mason TV episode, "The Case of the Duplicate Daughter."

Helm drew national recognition as Holly Jones, the love interest of Elvis Presley in his 1962 film Follow That Dream.

David Brian played Walt Douglas, an official of the stage line, who arrives in Laramie seeking his estranged daughter, Alicia, portrayed by Helm.

In the Gunsmoke TV Series she played "Helena Dales" in "One Killer on Ice", and "Trudy Trent" in "Bad Seed".

In 1963 she also guest-starred as Janie in Season-three of CBS's TV series Route 66 in the episode: "Narcissus On An Old Red Fire Engine".

[8] She also appeared in two episodes of the ABC Western series The Big Valley, both times in a role that interacted prominently with main cast member Lee Majors.

Helm then returned on March 4, 1968, in the third season in the episode entitled "The Devil's Masquerade," playing the role of Nancy.

In 1967 she appeared as Jeanne Springer in Season 3 Episode 16 "Long Time Dead" of Twelve O'Clock High.