Maria Juliana Barrera was born circa 1758, the daughter of Santiago Barrera and Maria Salome Garcia.
She married Jose Flores on 26 May 1784 in Mier.Their padrinos were Juan Angel Saenz and Maria Petra Garcia.
In 1782, she lived in Mier. The church census recorded that she was an unmarried girl, española, and 24 years old. Her household included 10 people:
Don Santiago Barrera, español, married, age 57. He owned Rancho San Salvador but did not live there.
Doña Maria Salome Garcia, española, married, age 43.
Jose Antonio Barrera, español, single, age 29.
Jose Ramon Barrera, español, single, age 19.
Maria Gertrudis Barrera, española, an unmarried girl, age 16.
Maria Juliana Barrera, española, an unmarried girl, age 24.
Maria Guadalupe Barrera, española, an unmarried girl, age 16.
Jose Angel Barrera, español, a youth, age 13.
Francisco Antonio Barrera, español, a child, age 11.
Ana Javiera Barrera, española, a child, age 3.