Maria Petra Longoria was born circa 1770, the daughter of Vicente Longoria and Manuela Francisca Garza.
She married Jose Antonio de Alanis on 1 Jul 1785 in Mier.
In 1782, she lived at La Bonita/ San Nicolas. The church census recorded that she was an unmarried girl, española, and 12 years old. Her household included 6 people:
Jose Vicente Longoria, español, married, age 59.
Ana Francisca Garza, española, married, age 43.
Maria Petra Longoria, española, an unmarried girl, age 12.
Jose Tomas Longoria, español, a child, age 10.
Jose Casimiro Longoria, español, a child, age 8.
Juan Jose Longoria, español, a young child, age 5.