She studied under Charles Paddock, Virginia MacWatters and Norma Newton, and was Co-Director (with Milton G. Scheuermann, Jr) of the New Orleans Musica da Camera, which specialises in music of the Middle Ages and the Renaissance, and has toured throughout the Gulf South.
St. Julien also appeared with The New Opera Theatre (as Dido in Dido and Æneas, her New York debut at Symphony Space, 1988), Pro Arte Chorale (Amor in a Concert Version of Orfeo ed Euridice, opposite Derek Lee Ragin), Louisiana Philharmonic Orchestra (Messiah), Great Neck Choral Society, International Dvořák Festival, Lyric Opera of Dallas, New Orleans Opera Association, Southwest Chamber Orchestra, Jefferson Performing Arts Society (Bach's Magnificat), etc.
In 1997, the soprano was Dircé in the Opera Quotannis Médée, opposite Phyllis Treigle and D'Anna Fortunato, at Alice Tully Hall, Lincoln Center.
This was the uncut, original opéra-comique version of the Cherubini masterpiece, and St. Julien was possibly the only singer in the twentieth century to sing the florid, difficult role complete and unadulterated.
At forty-two years, Continuum is the longest-running Early Music radio program in America, if not the world.