Although five years his senior, Blake was a niece of actor Milburn Stone, who filled the role of Doc Adams on CBS's Gunsmoke Western series. She did not begin to study acting until she was 50 years old, when she enrolled at the Pasadena Playhouse and took advantage of whatever influence or contacts Milburn Stone had to land acting roles. In the middle 1950s, Blake appeared on Rod Cameron's City Detective syndicated crime drama and in Ray Milland's sitcom, Meet Mr. McNutley, renamed in the second season as The Ray Milland Show. Blake appeared in four episodes of the NBC sitcom It's a Great Life (1954–1956) and twice on CBS's December Bride, with Spring Byington.
Blake portrayed gushy gossip columnist Dora Bailey in Singin' in the Rain (1952) and was a model for one of the fairies in Walt Disney's animated version of Sleeping Beauty (1959). She appeared as Mrs. Porter, a babysitter, in the 1959 pilot of CBS's Dennis the Menace. About this time, she was cast in a guest-starring role in the sitcoms, Guestward, Ho!, with Joanne Dru on ABC, and Angel, with Annie Fargé on CBS. In 1961, she guest-starred in the episode "A View of Murder" of the syndicated crime drama The Brothers Brannagan. Blake's Flora MacMichael was a romantic foil to Walter Brennan's Grandpa Amos McCoy on The Real McCoys, a situation comedy about a West Virginia mountain family that relocated to Southern California.
Prior to her role in Batman, she had a recurring role on The Jack Benny Program as the President of the Jack Benny Fan Club - Pasadena Chapter. She played Millie Brinkerhoff in the episode "Instant Wedding" in the 1963 NBC military drama The Lieutenant starring Gary Lockwood in the title role. Blake appeared in the pilot episode of The Addams Family (broadcast in the U.S in September 1964) as Miss Comstock, an official from the Addams' children's school. Blake also appeared in a memorable episode of I Love Lucy in 1957 with George Reeves guest-starring as Superman and in an earlier episode in 1954 as store clerk, Mrs. Mulford. She played the mother of Joey Barnes on the Joey Bishop show from 1961 to 1964. At one point, the producers of Batman wanted to fire Blake for unknown reasons. Adam West, with whom she had become friends, stood up for her and she kept her job. The next day, he found a freshly baked cake in his dressing room.
