Little is known about the early life of Martínez, other than that she was enslaved by President Francisco Solano López.
[6][7] When she witnessed the wounding of Major Francisco Ozuna, she was inspired to attack the enemy with a sword.
This act persuaded her comrades and other wounded soldiers to rally and stop the advance of the Brazilians.
[4][8][1][9] As a result of her intervention and her fighting, the newspaper El Semanario nicknamed her "the American Joan of Arc".
Páginas históricas de la Guerra del Paraguay, which, according to historian Carolina Alegre Benitez introduced women, including Martínez.