In 1937, Ernestine married Robert M. Lucas of Springfield, and later gave birth to three children. As an educator, Ms. Lucas taught at the Tennessee State School for Delinquent Girls, the Sleighten Farm School in Pennsylvania, the Ohio State Department of Vocational Rehabilitation and Springfield City Schools. She was also very active in the Springfield community, working with the Second Missionary Baptist Church, Girl Scouts, YWCA, Planned Parenthood and more. 

After she retired from teaching, Ms. Lucas spent years researching the history of early Black Springfield families as well as the genealogy of her own family. She taught Genealogy for the Community Schools, was active in the Afro-American Historical and Genealogical Society, of which she was a charter member, with the American Family Research Association and with the National Afro-American Museum and Cultural Center of Wilberforce, Ohio. 

Ms. Lucas published two books, "From Paris to Springfield: The Slave Connection, Basey-Basey," and "Wider Window to the Past, African-American History from a Family Perspective" exploring the genealogy of African American families around Springfield. Ms. Lucas died June 24, 2005. 

She is interred at Ferncliff Cemetery in Section 29, Lot 34 and is featured in the Trailblazers Tour of Prominent African Americans at Ferncliff.