Born in El Valle del Espíritu Santo, Mariño was raised in a wealthy family.
Her parents owned estates on the island of Trinidad and eastern Venezuela, including one on the islet of Chacachacare and another in Delta Amacuro.
Mariño played a key role, taking charge of weapons smuggling from Trinidad to the mainland to be used by the troops of Simon Bolivar, though this caused a lawsuit under the authority of British martial law.
It included the drafting and signing of the Acta Chacachacare by Santiago Mariño, Francisco Azcue, Jose Francisco Bermudez, Manuel Piar and Manuel Valdes, which mentions Mariño as a "magnanimous woman", and started the Campaña de Oriente.
[1] In 1821, when Venezuela was facing the threat of Miguel de la Torre, Mariño was involved in shipping weapons from Jamaica for the Bolivar Army.