 Branchu was one of the first students at the Paris Conservatoire after it opened in 1795, and studied singing under Pierre Garat.Although Branchu frequently performed works by Christoph Willibald Gluck and was notable for roles in "Anacréon" and "Les Abencérages" by Luigi Cherubini, she is best remembered for her performances in the title role of Gaspare Spontini's most important opera, "La vestale" (1807).She also performed in Spontini's "Fernand Cortez" (1809) and "Olympie" (1819).