Known as Juliette, Louvet was the daughter of Jacques Henri Louvet (1830 - 1910) and his first wife, Joséphine Elmire Piedefer (1828-1871).
She married photographer Achille Delmaet on October 6, 1885 (his best known photographs are nudes of La Goulue, a cancan dancer of the Moulin Rouge). The Delmaets were divorced on January 14, 1893; they had two children, Georges (1884-1955) and Marguerite (1886-1894).
Juliette Louvet became an entertainer of sorts, reportedly a cabaret singer (other sources identify her as a laundress and a dressmaker), then was Prince Louis's lover. She gave birth to their daughter, Charlotte, in Algeria on September 30, 1898.