Akuyaku wo Yametara Gitei ni Dekiai Saremashita

Reincarnated as the daughter of a duke from a novel she wrote in her previous life, Lelia realizes she is the villain who bullies and kills her cold, expressionless, handsome stepbrother, Rudy. While trying to avoid the worst-case scenario by loving and caring for her younger brother, for some reason, he begins to approach her...!?

(Source: Comic Walker, translated)