Barnes was born in Robeson County, North Carolina, USA, on 5 November 1875, to parents Evander Daniel Pittman (1844–1927) and Sarepta Amelia Thompson (1852–1930). She had at least five siblings: Emma Gaddy (1878–1920), Benjamin Ernest Pittman (1888–1965), Nellie Vivian Warner (1891–1987), Ada Virginia Best (1893–1991), and Nina Pittman. She grew up on the county, attended local schools, and taught school for several years before getting married.

On 26 February 1902, she married Luther Belden Barnes (1874–1964). The couple had two children: Marguerite (married Leggette) and Bahnson Neill Barnes (1903–1996). Her husband taught school near Bladenboro for many years. Both of her children went on to become teachers. She had been a member of Back Swamp Baptist Church since the age of 12, teaching Sunday School there for 50 years. Additionally, she was a charter member of the Women’s Missionary Society. Remaining active in the community well into her centenarian years, she held various offices in the Back Swamp Home Decoration Club. Moreover, she held an honorary membership in The Challengers Club, which succeeded the home demonstration club.

In November 1975, she was honored twice in one week in celebration of her 100th birthday. She received a special tribute at the annual Homecoming of the church, where the pastor presented her with a silver tray. Additionally, she was gifted a lavender orchid corsage along with an arrangement of yellow Fuji mums and pompons. At the age of 107, she had two living sisters, two children, three grandchildren, and four great-grandchildren.

Barnes passed away in Lumberton, Robeson County, North Carolina, USA, on 6 May 1986, at the age of 110 years, 182 days.