After going to Inmaculada Concepción for schooling, Minerva realizes the truth about her country and Trujillo (she got "free"--enlightened). The "cage" represents Trujillo's dictatorship, its oppression, and how it takes away the people's freedom.
The water from the storm here represents the ubiquitous influence of Trujillo's power. The country is saturated in it. When Minerva slaps Trujillo at a dance, a long series of events is set off, symbolizing a storm for the Mirabal family. This quote also connects with the novel's theme of authoritarian and political control.
Maria Teresa and Minerva are detained at La Victoria, a prison. Maria Teresa writes this in her journal that was smuggled in. The prisoners have been starting to wear crucifixes as a demonstration, but Trujillo has ordered them to be confiscated. As Minerva is brought to solitary for resisting and refusing to take off her crucifix, the prisoners call out "¡Viva la Mariposa!" Quisqueya is the original native name for the island that encompasses the Dominican Republic and Haiti. This quote also shows the theme of courage (versus cowardice) in the novel.
Even living miserably in prison, Maria Teresa sometimes feels the deep bond between her and all the other "women politicals." They are united in the sense that they are fighting for the freedom of their country and are willing to sacrifice themselves for the greater good and for their country.