At college, she won "The Chancellor's Award for Excellence in Theatre", a one-year scholarship which enabled her to transfer to the University of California, Riverside, as a sophomore.

[8] In 1973, when her scholarship expired, Tewes withdrew from college and joined the Pacific Conservatory Theatre in Santa Maria, California, as an apprentice, making her stage debut in Arsenic and Old Lace and The Most Happy Fella before becoming a member of the Birdcage Theatre Company at Knott's Berry Farm, an amusement complex outside Los Angeles.

[9] Tewes' first break came in mid-1974 when she starred in a Lipton Ice Tea commercial, allowing her to join the Screen Actors Guild and register with an agent with the prospect to work on film projects.

[11] She starred in the third and final pilot of the show, cast the day before production began on the RMS Queen Mary in Long Beach.

[16] As well as doing voice-overs for commercials, Tewes continued her TV career and appeared in a 1998 episode of Love Boat: The Next Wave, a two-season revival of the original series.

[18] Tewes has been married three times: first to John Wassel, a TV commercials director; then to Paolo Nonnis, an Italian drummer; and, lastly, to stage actor Robert Nadir.