De la Cruz became engaged to Aníbal Pinto after he returned from a long trip in Europe, and they married on 24 November 1855 in Concepción.

Animosity had arisen between the cities as a result of the 1851 Chilean revolution, during which uprisings had taken place in Concepción against the central government based in Santiago.

Pinto was elected president of Chile in 1876, and de la Cruz accompanied him to all government ceremonies, even inspecting the troops in his company during the War of the Pacific.

Under the pseudonym Delfina Perez, de la Cruz published 12 works throughout the 19th century, surpassed in volume only by Isidora Zegers.

Several of her pieces also attained international recognition, including "The Star of Night" ("Spanish: La estrella de la tarde"), a polka for piano which was played in Paris, as well as "Armando the Gondolier" ("Spanish: Armando el gondolero"), a waltz for piano later performed in Germany.