Most of the information regarding Catherine Mattei is derived from a vita written by her friend, John Francis Pico, Prince of Mirandola.

She would also begin to have visions of other saints such as the Dominicans Catherine of Siena and Peter Martyr.

The Virgin told her that Jesus wanted to have her as his bride, as a token of which she was given a wedding ring, which she had all her life—but which only she could see.

Many miracles would result from her visions: a broken dish was made whole again, and money and food would be provided when the family's poverty was extreme.

[2] Her mystical experiences roused a storm of gossip among her neighbors, who were terrified at the lights and sounds that came from her home; even the Dominican friars began to ostracize her.