Amy was born in New York State, according to the 1860 US Census of Ionia County, Michigan. In 1860, at the age of 19, she was living with the John and Elethea Dunlap family. They lived next door to the family of Joseph and Lucy Mosher. She may be a relation to that Mosher family.
On June 11, 1863, Amy married Charles H. Barnum, a son of Smith Barnum and Freelove Mason. The marriage took place in Lyons Township, Ionia County, Michigan at the home of Mr. L. Willis. The wedding was presided over by Rev. Levi Ferguson, a Methodist Episcopal Minister.
Amy and Charles had one child, a daughter named Edith Barnum, who eventually married George Austin Cathey.
A death notice from the Greenville Independent, February 1, 1905, Volume 48, Number 5, Page 1 states that "Mrs. Charles Barnum, of Greenville, died after a long illness of Cancer of the stomach."
Amy is buried next to her husband Charles in the Forest Home Cemetery.
Death: Jan. 30, 1905. Inscription: ae 65/8/8. Burial: Forest Home Cemetery, Greenville, Montcalm County, Michigan, USA.