Florence Vallejo Terronez was born in Horton, Kansas, in 1924 to Martina Morado and Julio (Julius) R. Vallejo. Martina Morado was born in Guanajuato, Mexico, and came to the United States in 1910 when she was thirteen years old with her mother, Angela Morado, and her brother. The family settled in the railroad town of Horton, Kansas, where the children helped their mother run a boarding house.

In 1914, Martina Morado married Julio Vallejo, who was born in Leon, Mexico, and had come to Horton at the age of sixteen where he was employed as a pipefitter on the Rock Island Railroad. He also managed the Horton baseball team, was an accomplished singer, and ran a barber shop out of his home. The couple raised eleven children. Julio Vallejo, like many railroad workers, was laid off during the Depression, and for two seasons the entire family worked the beet fields in Minnesota in order to make a living. In 1941, when the railroad in Horton closed down, the family moved to West Des Moines, Iowa, where Julio Vallejo continued to work as a pipefitter for the Rock Island Railroad.

Florence Vallejo attended school in West Des Moines. During the 1940s and 1950s she continued to live with her family working as a nurse's aide at Broadlawns Medical Center and as a long distance telephone operator for the Northwestern Bell Telephone Company. She was employed as a welder for Solar Aircraft Company for two months in 1945, a job that came to an abrupt end when it was announced that World War II was over. In 1956, Florence Vallejo married Antonio (Anthony) Terronez, an architectural engineer who worked for John Deere and Company in East Moline, Illinois. Terronez was a widower whose first wife had died in 1951, leaving him with four young children to raise.

Following her marriage, Florence Terronez became a full-time mother, managing the household and caring for her four stepchildren and two more children who were born later. She was involved in her children's school and church activities, sang in the church choir, and later worked as a nurse's aide at St. Anthony's Hospital in Rock Island, Illinois. Following her retirement she volunteered with the Genesis Medical Center in Silvis, Illinois, and served on the community service auxiliary of the Veterans of Foreign Wars post in East Moline, Illinois.