Marie-Elizabeth was a painter, a student of Camille Roqueplan, and was married to the painter Clément Boulanger.
She met Delacroix during the famous masked ball at the 1833 Carnaval organized by Alexandre Dumas. A love affair blossomed between the two painters, although after an escapade in Flanders in September 1839, their relationship transformed into a deep friendship, tinged with nostalgia.
In 1843 she was remarried to François Cavé, then head of the Beaux-Arts at the Interior Ministry. In 1860 she published an essay on drawing, which was reprinted in 1862, with a preface by Delacroix.