[eng] Rose et Blanche written by Aurore Dudevant and Jules Sandeau, under the pseudonym of J. Sand, raises the question that always arises with a collaborative work: What is the contribution of each of the authors? Denied by the writer herself, the role of this novel is nevertheless decisive in the birth of the future George Sand. Through her correspondence and her Histoire de ma vie, among others, we will try to determine what this work meant for the 'literary schoolgirl', before focusing on three major themes, resulting from her personal experience, which mark out this novel (monastic life, marriage and the Pyrenees) and which reveal her immense contribution.