Charrière’s epistolary relationship with these two members of the Constant family is representative of the originality of her subject-position as a woman writer in the eighteenth century. Her exchanges with the uncle and then with the nephew constitute two singular and self-consistent groups of letters in her general correspondence, each proving equally significant for her development as a publishing author. And, crucially, one must underline the equalitarian tone of her letters to David-Louis Constant d’Hermenches (1722-1785) and, later, to Benjamin Constant (1767-1830). Neither gender nor age inflect the way they wrote to one another. Charrière’s correspondence with them appears to have been, on the contrary, an exceptionally free and transparent mode of exchange, clearly distinct from the conventions regulating the social space. Writing letters to d’Hermenches and Constantinus (as she named them) enabled her to invent and articulate a form of relationship unavailable in real life: freedom of speech between a man and a woman, and between generations. Based on a few examples, this presentation is going to focus on how writing to the Constants may have contributed to the forging by Charrière of her exceptionally autonomous and assertive voice as a progressive female author of the Enlightenment.