[1][2] Hansell was born in Bridgeport, Connecticut and studied as an undergraduate at Wellesley College, receiving her BA in 1963.
Her doctoral dissertation was entitled Opera and ballet at the Regio Ducal Teatro of Milan, 1771–1776: a musical and social history.
She worked as an organist and teacher in Illinois from 1967 and at Grinnell College in Iowa from 1976.
From 1982 she was an archivist at the Swedish Music History Archive in Stockholm and in 1987 edited Volume 14 of the complete works of Swedish composer Franz Berwald for the Monumenta musicae Svecicae series.
She later worked for many years as the acquiring editor for music at University of Chicago Press and was the managing editor of the publisher's Works of Giuseppe Verdi series.