Gregory IX, Pope. [Letter to Agnes of Prague, 1238 (4)] in Bullarium Franciscanum Romanorum Pontificum 1.241-42

[Letter from Pope Gregory IX to Agnes of Prague]
The pope praises Agnes for her vocation and encourages her in rather involuted language to continue the traditional functions of a nun, pointedly avoiding the subject of Franciscan practices, though he does talk about Francis, the stigmata, and the three orders.
Online at Epistolae (See also Bibliographia record).