She was the 5th of 6 children born to Enos Mitchell Campbell and Matilda Tabitha (Hill) Campbell in Walker Co., GA.
Mary's father was a Confederate soldier during the Civil War, when he was captured and died of small pox at Rock Island Prison in Illinois. Mary was only 4 years old and her mother never remarried. Shortly after the war ended, Mary's mother picked the family up and moved to East Texas with other members of the Campbell family.
Mary Elizabeth married George Washington Cornelison in about 1877 in Grayson Co., TX. George had been previously married and came to Mary with seven children to raise. She was small of stature and cripled in one arm, but she not only helped George raise his seven children but also gave birth to 13 of her own.
Their children were:
George Enos Cornelison Spicey Cornelison Matilda Cornelison Archie Porter Cornelison Bertice Oma (Cornelison) LeDerer Annie Clarentine (Cornelison) Hansen Effie May (Cornelison) Keen Homer Ira Cornelison Carrie E. Cornelison Zada G. Cornelison Ila O. "Babe" Cornelison Claude Douglas Cornelison Leroy R. Cornelison