As one of the first Mexican American female radio announcers in the early 1930s, Hernandez spoke out against the economic discrimination and educational segregation suffered by women and children of Mexican descent.
Born in 1896 near Monterrey, Mexico, Hernandez worked as an elementary school teacher before moving to San Antonio, Texas, to raise a family as well as run a grocery store and bakery. In 1929, she helped organize the Orden Caballeros de America (Order of the Knights of America), a group dedicated to educating Mexican Americans about their rights. In 1933, she co-founded the Asociacion Protectora de Madres (Association for the Protection of Mothers), which gave aid to expecting mothers.
Hernandez took to the San Antonio airwaves in 1932 to protest injustice and inequality in the Mexican American community and used the Voz de las Americas program to promote the League of United Latin American Citizens, a Latino civil rights organization.
Hernandez spent the rest of her life writing and speaking publicly for the rights of Mexican Americans.
She died of pneumonia in 1986 at the age of 89.