Lord El-Melloi II's adoptive younger sister, and the next head of house El-Melloi that has brought the family together out of the hardships suffered in their downfall. She was the one who gave him the name "El-Melloi" and the seat of the Lord. At times, she seems to enjoy giving her new adopted brother completely unreasonable demands and seeing how he reacts to them.

(Source: elmelloi-anime.com)