St. Agnes of Montepulciano, entered the convent at the age of 9, commissioned by the pope to found a monastery at the age of 13 (and 2 years later she was made its superior), also founded a Dominican convent, d. 1317.

Hagiography of St. Agnes of Montepulciano.

St. Agnes of Monte Pulciano, virgin and abbess. From Alban Butler's Lives of the Saints.