Stagel was born into a noble family of Zurich, the daughter of a councilor.
She developed a deep friendship with Henry Suso, and the two remained in active correspondence. Suso considered Stagel his spiritual daughter. During their meetings, Stagel asked Suso to help her understand the pathway to God by sharing with her his own experiences. However, Suso did not know that the well-educated nun was keeping the letters he was sending to her and writing down all that Suso was telling her, which did not include only theology, but also his extreme practices of penance. Stagel gave him her writings when he learned about them and he proceeded to burn them, saving only the second installment of manuscripts for the sake of educating other religious persons. Suso forbade Stagel to imitate him by engaging in extreme asceticism, fearing for her health.
The historicity of Stagel as the author of the Lives of the Nuns of Töss, a work containing biographies of 39 nuns and providing a comprehensive picture of mysticism in the Töss Convent, is subject to debate. Blessed Elizabeth of Hungary may have been one of the nuns whose life Stagel described but this allegation has been particularly disputed because the book portrays Blessed Elizabeth's stepmother, Agnes of Austria, dowager queen of Hungary, very negatively; it is highly unlikely that such a biography was written before the death of Queen Agnes who outlived Stagel, dying in 1364.
Stagel died in Töss. Stagel's work is integral to understanding mysticism and monastic life in medieval Germany.
- Kroll, 166.
- Classen & Sandidge, 483.
- Duggan, 116.
- Classen, Albrecht; Sandidge, Marilyn (2011). Friendship in the Middle Ages and Early Modern Age: Explorations of a Fundamental Ethical Discourse. Walter de Gruyter. ISBN 3110253984.
- Duggan, Anne J. (2002). Queens and Queenship in Medieval Europe: Proceedings of a Conference Held at King's College London, April 1995. Boydell Press. ISBN 0-85115-881-1.
- Kroll, Jerome (2005). The Mystic Mind: The Psychology Of Medieval Mystics And Ascetics. Routledge. ISBN 0415340519.
Further reading 
- Oehninger, Robert H.: Wir hatten eine selige Schwester... 33 Lebensberichte über Dominikanerinnen aus dem Kloster Töss bei Winterthur. Werd Verlag, Zürich 2003
- Stagel, Elsbeth: Das Leben der Schwestern zu Töß. Rotapfel-Verlag, Erlenbach-Zürich, 1923.