Julia was born in Mississippi in 1844 to Rhode Islander Asa Watson (1812-1886) and his wife Ede Tennessee Taylor (1824-1888). Four younger siblings followed: Wheeler Rufus 1847, Henry Duke 1850, Tennessee T 1856, and Lydia 1857.
In 1866 Julia married Confederate Lt Col Peyton Manning, 6 years her senior and a native of Alabama. They had no known children and she was widowed only two years after their marriage when she was 24 years old. Apparently she resumed living with her parents and is listed with them in the Lowndes County census of 1870 and 1880.
After 26 years as a widow, Julia married again in 1894. Her second husband was Dr Burrell Alexander Duncan, a South Carolina native, 9 years her senior who had been widowed 4 years earlier after a 32 year marriage with 3 children. This marriage lasted 6 years until Julia's 1902 death at age 58. Her husband outlived her by 14 years succumbing to a cerebral hemorrhage at age 81 in Missouri where he had been living with his daughter Ann Duncan Blackwell.
Julia had been predeceased by her sister Lydia (childbirth at 21). Both her brothers died in 1911. The youngest sibling, Tennessee, wife of Benjamin L Owen. lived to be 87.