Susana Alexander was born in North Carolina on December 24, 1759. A great deal of contradictory evidence exists about Susana Alexander's early life and family. Susana herself states that her father's name was James Alexander, though she may have misspoken or the clerk may have written it down incorrectly, confusing the last name of her father with that of her husband. Other sources written by people that claim to have known her suggest that her last name was either Smart or Wilson, both of which were prominent families names living in the Mecklenburg County area at the time. Without definitive evidence such as a father's will or a marriage bond, it is impossible to say with certainly what her last name was. Consequently, editors have deferred to the maiden name of Alexander which Susana stated in her pension application.

Susana married John Alexander in Mecklenburg County on November 12, 1777. After their marriage, John Alexander went out in service as a private for the Patriot cause. He was away for at least nine months in 1779, though Susana later recalled that he was away in service for almost the entire length of the war.

In September 1780 while covering the troops retreating from Charlotte, Col. Joseph Graham was knocked from his horse, attacked by British dragoons and left for dead. After dragging himself to a nearby spring for water, Susana Alexander came across him. She put him on her pony and brought him to her mothers house, where she hid the wounded colonel overnight and tended to his wounds. The next morning a British officer's wife visited the Alexander home and when she discovered that they were hiding a wounded Patriot officer, offered to return with a British surgeon who could treat him. Fearing that they would take Graham prisoner, the Alexander's alerted some of the colonel's men, who helped evacuate him north behind Patriot lines where he could recover from his wounds. Graham later credited Susana's efforts with saving his life.

When her husband died on July 12, 1805, he and Susana had at least four children whom were still living; Asseneth, Matilda, Susanna and Matilda. Susana Alexander never remarried and continued to live within the confines of the Sugar Creek Congregation of Mecklenburg County for the rest of her life. A widow for over fifty years, she was affectionately known as "Aunt Susie" within the local community. In order to support her family, Susana Alexander worked as a midwife. One contemporary also noted "her aversion to [American] Indians [and] her fondness for her pigs."

In 1845 her reputation as a storyteller generated national attention when newspapers in Washington, DC challenged her story that future present Andrew Jackson and his mother had stayed at her family home while fleeing from British troops in the area. Although she painted a colorful tale of "Ande Jackson," the young bow hunter who helped her tend to the family crops and nurse her infant, but Jackson's biographers disputed many of the detail of her story, denouncing it as a tall tale. The newspapers also denounced her story about saving Colonel Joseph Graham, but several prominent citizens, including Graham's grandson later vouched for her heroic efforts as saving the wounded colonel from the battlefield.

In 1846 she applied for a widow's pension based on her husband's military service during the American Revolution, but did not attach enough requisite evidence to prove her claim. She renewed her efforts in 1851. This time she was endorsed by William Alexander Graham, the current U.S. Secretary of the Navy and Col. Joseph Graham's son. This application was successful was she was granted $30 a year from 1831 until the time of her death. She died in Mecklenburg County on June 11, 1856.