Who's asking: An anonymous Google searcher from somewhere in North America
St. Monica (333-387) was the mother of St. Augustine (354-430). Monica's husband, Patritius, drank and beat her until Monica's patience and prayers helped to change his nature, and won his conversion to Christianity. Monica's charity and faithfulness annoyed her son Augustine, but ultimately inspired him, and her constant prayers are credited with Augustine's conversion from Manichaeism to Catholicism. She was the one who introduced Augustine to St. Ambrose, who became Augustine's mentor and confessor. Monica is the patroness of the Archconfraternity of Christian Mothers, whose object is mutual prayer for straying sons and husbands.
Today we would call St. Monica co-dependent, and urge her to seek treatment; she would probably leave Patritius, wash her hands of Augustine, write a self-help book and host a talk show. I'm not sure this is progress.
The California city of Santa Monica is named because explorers found it on St. Monica's traditional feast day, May 4. Since Vatican II, the church has celebrated the feast of St. Monica on August 27, the day before the feast of St. Augustine.