This paper describes the manuscript, dated 1664, which reflects the Venerable Mother María Bautista's life from the Commanders of Santiago de Toledo's convent as a biography or nuns' «life». Nuns' «lives» were written in the convent, which at that time was a privileged space for women's writing intended as edifying narrative. Mary Baptist's biography, part chronicle, part inspirational discourse, shows the basic structure of this kind of speech and when an exemplary narrative is built, stands a model of holiness whose ultimate goal is to develop the paradigm of «Christ's wife».