Rush first worked as a series regular playing a Washington newspaper correspondent in "Saints and Sinners" (NBC, 1962). She garnered some notice for her season-long (1968-69) stint as Marcia Russell on ABC's primetime soap "Peyton Place". Rush then tried her hand at comedy, portraying a temperamental soap opera star on "The New Dick Van Dyke Show" (CBS, 1973-74). In the early 80s, it was back to the real thing as the matriarch Eudora Weldon on NBC's "Flamingo Road" (1981-82) and a brief turn on ABC's daytime staple "All My Children".
Approaching the age when actresses find roles difficult to land, Rush stayed active on stage appearing throughout the USA in such fluff as "Forty Carats" and "Same Time, Next Year". She commissioned and earned rave reviews in the solo theatrical piece "A Woman of Independent Means", based on the novel by Elizabeth Forsythe Hailey in New York and Los Angeles. More recently, Rush returned to the small screen appearing in the recurring role of Stephen Collins' mother in "7th Heaven" (The WB).