There are questions that I have answered related to imageries that bring out the theme of Superstition. You can check the response to those questions.
Here, I will provide a different theme, Death.
1. Thoni tells the woman she longs a country where light doesn't exist. A country where there are no people. A country she had experienced while young. Darkness represents death. In death, there is no light. In death its total darkness. You can see anybody or hear anyone. You only exist alone in death.
2. The woman who was urging Thoni not to kill herself hands Remi a letter. She says, "She was kind. She who was true. A tender sapling growing straight though surrounded with weed.” The woman was talking in past tense indicating it is an action that was completed. Thoni had committed suicide the reason the woman is very angry at Remi.
3. Remi kneeling beside the dead body of Thoni who was being carried on a stretcher, mourning her death.