Mary A. Monks (maiden name: Donoho) was born on September 26, 1825, in Maryland to Stephen Donoho and Sarah Wilcox. She grew up in Cecil County, Maryland. Her father probably died by the early 1830s, and her mother married Hugh Hamilton on May 20, 1835.
She married Thomas Monks, and they had at least five children: Anna, born on April 10, 1844; Sarah, born around 1845; Lydia, born around 1847; John, born around 1850; and Isabella, born around 1852. They lived in Pocopson, Pennsylvania, and her husband worked as a plasterer. By 1850, they owned $500 of real estate. She died in Kennett, Pennsylvania, on September 30, 1876.