When Stella Slaby was born on 1 April 1898, in Independence, Trempealeau, Wisconsin, United States, her father, Thomas Slaby, was 48 and her mother, Anna Filla, was 45. She married Milton Peter Mercier on 23 June 1941, in Olmsted, Minnesota, United States. She lived in Trempealeau, Wisconsin, United States in 1920 and Lemmon, Perkins, South Dakota, United States in 1930. She died in 1986, at the age of 88, and was buried in Calvary Cemetery, Arcadia, Trempealeau, Wisconsin, United States.