Marcus was a student of Lee Strasberg. She appeared in numerous television shows throughout the 1950s and 1960s, sometimes billed as Dolores Vitina. She was cast in Irwin Allen’s 1960 production of The Lost World, as well as Taras Bulba with Tony Curtis and Yul Brynner. She appeared in two episodes of Lost in Space as “The Green Lady”, Dr. Smith’s most persistent and verdant admirer. She also appeared in Voyage to the Bottom of the Sea, including the second-season episode “Return of the Phantom”; Have Gun – Will Travel as Della White Cloud, an Apache princess, and in episodes 24 and 26 of The Time Tunnel, “Chase Through Time” and “Attack Of The Barbarians”. She starred in the TV series, Gunsmoke episode, “The Squaw” as Natacea (1961). In 1962, she portrayed the role of Wahkshum, in the episode “The Peddler”, of CBS’s Rawhide.