Emma Lathrop was born around 1851 in Ohio to John W. Lathrop and Eliza Jeanette Calloway. Her father was a carpenter who owned $150 of personal property by 1860. She grew up and attended school in Austinburg, Ohio, and she married Oliver J. Steward on September 25, 1873. They had at least eight children: Anna, born around 1875; Caroline, born around 1876; Oliver, born around 1879; Bessie, born around 1882; Junius, born around 1886; Wilfred, born around 1890; Frances, born around 1895; and Jane, born around 1897.
They settled in Buffalo, Minnesota, and her husband worked as a superintendent of schools. They moved to Ellensburg, Washington, in the late 1800s, and then to East Sunnyside, Washington, in the early 1900s. Her husband died on March 24, 1932. By 1940, she was living with her daughter Caroline in Yakima, Washington. She died in Port Angeles, Washington, on August 6, 1940.