She was a daughter of Stephen Adams and Abigail unknown.
In the 1850 US Census for New Fairfield, Fairfield County, Connecticut the family of the widow Eliza (Adams) Barnum was enumerated as follows:
Dwelling #88; Family #99
Eliza Barnum, 47, F, b. Connecticut
George Barnum, 23, M, Bootmaker, b. Connecticut
Mary E. Barnum, 17, F, b. Connecticut
Stephen Barnum, 11, m, b. Connecticut, Attended school within the year
Gravestone inscription: Farewell vain world, I am going home; my Saviour smiles and bids me come; and angels beckon me away to sing God's praise in endless day.