Lota, as she was known, maintained a lesbian relationship with the American poet Elizabeth Bishop from 1951 to 1967. Their relationship is depicted in the Brazilian film Reaching for the Moon, based on the book Flores Raras e Banalíssimas (in English, Rare and Commonplace Flowers), by Carmem Lucia de Oliveira, as well as in the book The More I Owe You, by American author Michael Sledge.
In 1967, Soares followed Bishop back to the United States, having recovered from an ailment with extensive hospitalization. The same day she arrived in New York, 19 September 1967, Soares took effective steps to commit suicide by overdosing on tranquilizers, and died several days later.
Elizabeth Bishop, One Art: Letters. Ed. Robert Giroux (New York: Farrar, Straus, Giroux, 1994).
Carmen L. Oliveira, Rare and Commonplace Flowers: The Story of Elizabeth Bishop and Lota de Macedo Soares, translated by Neil K. Besner, (Rutgers University Press, 2002); reviewed by Emily Nussbaum 
Schuma Schumacher and Érico Vital Brasil, eds. Dicionário Mulheres do Brasil (Rio de Janeiro: Jorge Zahar Editora, 2000), pp. 335-336.
Michael Sledge, "The More I Owe You." (Berkeley: Counterpoint Press, 2010).