Agnes of Assisi. [Letter to Clare of Assisi, 1230] in Analecta Franciscana 3.173-82

[Letter from Agnes of Assisi to Clare of Assisi]
A younger sister of Clare, Catharine secretly followed her sister into the monastery to the fury of her family, which had arranged a marriage for her. She prevailed, however, and renamed Agnes by St. Francis, she was sent to be abbess of St. Mary of Monticello in Florence in about 1229. In this letter, written shortly thereafter, she reveals how much she misses her sister and the other nuns, despite the good reception she has found.
Online at Epistolae (See also Bibliographia record).