This article analyzes the "Cartas sobre a educação das meninas por uma senhora americana" translated into Portuguese by João Cândido de Deos e Silva, attributed to the author José Joaquin de Mora. The work presents itself as a series of letters sent by an alleged "American lady", which prescribes forms of behavior, education and social conduct for women of the 19th century. The text questions anonymous female authorship, revealing the prescriptions and values imposed on women at the time, aiming to conform them to a patriarchal society. The analysis reveals authorship lapses present in the text, suggesting that the work was not actually written by a woman, but by a male author who hides behind the female pseudonym. Through possessive pronouns and other indications, the presence of an authorship alien to the female gender is evident, which raises questions about the motivations behind this artifice. The relevance of the work lies not only in its prescriptive content, but also in its historical and social impact. The text was disseminated in schools and recommended to teachers as a manual of conduct for their students, shaping the female mentality of the time and imposing a normative standard of behavior. In addition, the article emphasizes the association of the discourse with Catholicism, exploring desired characteristics for women, reinforcing the need for self-identification in the reading process. The research highlights the role of the social imaginary in the consecration of the work's prescriptions. The imaginary transcends into reality, influencing everyday practices, institutions and identities. Critical discourse analysis reveals how the imaginary manifests itself and is perpetuated in collective memory, configuring itself as a powerful normative instrument of social relations. Through this study, we seek to reveal the elements that make up the historical and identity construction of Brazilian women in the 19th century, allowing a deeper look at the work "Cartas sobre a educação das meninas por uma senhora americana" and its influence on society at the time.