When Nancy Rebecca Hayward was born on 10 December 1863, in Tazewell, Illinois, United States, her father, John Wales Hayward, was 35 and her mother, Mary Ann Wyckoff, was 33. She married James Monroe Slattery on 8 August 1883, in Vinton, Benton, Iowa Territory, United States. They were the parents of at least 2 sons and 1 daughter. She lived in Logan Township, Ida, Iowa, United States in 1910 and Los Angeles, Los Angeles, California, United States in 1930. She died on 12 June 1944, at the age of 80.