Washington was raised in Harlem, New York. In 1956, she joined the vocal group The Hearts, then became s a solo artist the following year. Washington had 16 rhythm and blues chart entries in 15 years, most of them during the 1960s. Most of her early work was released as singles.

Washington initially recorded on Donald Shaw's Neptune Records label. She established herself as a soul singer with two hits in 1959: "The Time" (U.S. R&B Top 30) and "The Bells" (U.S. R&B Top 20). She followed up with the hit "Nobody Cares" (U.S. R&B Top 20) in 1961.

She next signed with ABC Paramount, but her two releases for the label were not hits, although the self-written "Let Love Go By" later became a notable Northern Soul single.

Washington then moved to Juggy Murray's Sue Records in 1962, scoring her only entry on the U.S. Billboard Hot 100 Top 40 with 1963's "That's How Heartaches Are Made" (1963). Two years later, she hit again on the U.S. R&B Top 10 with "Only Those In Love". Among her other Sue recordings were "I Can't Wait Until I See My Baby's Face", written by Jerry Ragovoy, and "Careless Hands", penned by Billy Myles.

Washington revived her career in the early 1970s covering The Marvelettes' "Forever", (number 30 R&B) as a duet with Don Gardner. Her solo release, "I've Got To Break Away", made number 73 on the R&B charts, after which the advent of disco led to a decline in her popularity.

Washington has never experienced great crossover recognition, although Dusty Springfield cited Washington as her all-time favorite singer.

Washington is still active as a live performer, appearing several times a year on the East Coast. She performed with the Enchanters at a Philadelphia-area show in March 2008, and in Baltimore in June 2008. Washington was among the 2008 honorees in Community Works' Ladies Singing the Blues music series.