Agnes spent her childhood between her father's palace in the city and his castle of Sasso Rosso on Mount Subasio.

Sixteen days later, Agnes ran off to the Church of St. Angelo di Panzo where Francis had brought her sister, resolved to share Clare's life of poverty and penance.

[2] Angry at the loss of two of his daughters, their father sent his brother Monaldo and several relatives and armed followers to the monastery to force Agnes, if persuasion failed, to return home.

[1] Monaldo drew his sword to strike his niece, but his arm allegedly dropped to his side, withered and useless.

Agnes's body reportedly became so heavy, perhaps due to the help of her sister, that her assailants dropped her in a field nearby.

[2] Francis later established a cloister for Clare and Agnes at the rural chapel of San Damiano.

Agnes was said to be very virtuous, and as abbess she ruled with a benevolent kindness, knowing how to make the practice of virtue appealing to her sisters.