D'Aunet was by this time already living with Biard, and agreed to persuade her future husband to accept the position of official painter for the expedition, on condition that she be allowed to accompany him.

[3] She traveled with Biard across Belgium, Holland and Norway, before leaving Hammerfest, the northernmost city in Scandinavia, and returned after spending several weeks at Spitzbergen.

After two months, she was transferred to the Convent of the Ladies of Saint Michael, where Adèle Foucher (wife of Victor Hugo), who was glad to see a competitor to Juliette Drouet, decided to visit Leonie.

D'Aunet also devoted herself to the theater by writing the drama Jane Osborn, performed by Lucie Mabire, on 30 January 1856 at the Porte de Saint-Martin theatre.

She also had a daughter, Marie Biard [fr], who died in 1897, who bore in literature the pseudonym Étincelle ("Sparkle") and who successively married Viscount Peyronny and Baron Double de Saint-Lambert.