In 1986, Barker was awarded the Dame Mabel Brookes Fellowship and was a finalist in the Metropolitan Opera National Council Auditions. These accolades helped her to launch a solo career with minor opera companies during the late 1980s. She performed the roles of Marzelline in "Fidelio" and Cherubino in "The Marriage of Figaro" with the English Touring Opera. In 1989 she won the Royal Over-Seas League Competition in London. Her first major critical success came in 1990 at her debut at the Sydney Opera House as Mimì in Puccini's "La bohème", directed by Baz Luhrmann.