Answer:
She worries that Don Ricardo's curse will overcome their love.
Step-by-step explanation:
This excerpt shows how worried is Blanca Flor in the story and some keywords help you infer that she is afraid that Don Ricardo's curse will overcome their love, for example, "We have not escaped. His final curse will forever be over us." and "His powers are very great, Juanito." even when Juanito gives her evidence that her fear may not become true.