Vibrant, personable redhead who debuted onstage at age five, followed with radio's "One Man's Family" for six years, and racked up over 1000 radio and 50 TV credits by the time she was 16. St. John moved into features in the late 1950s and for the next decade was, like Ann-Margret, Tuesday Weld and many others, frequently typecast in sexpot roles in light comedies and adventures. Despite her fresh, good-humored and relaxed presence, St. John frequently played second fiddle to other actresses. In "Come Blow Your Horn" (1963) it was Barbara Rush, and in "The Oscar" (1966) Elke Sommer. Exceptions