Question: Princess Maria Gabriella of Savoy, is the middle daughter of Italy's last king, Umberto II, and Marie José of Belgium, the "May Queen", and a sister of which pretender to their father's throne, the only son of Umberto II, the last King of Italy, and his wife, Marie-José of Belgium?
Sentence (from "Princess Maria Gabriella of Savoy"): She is an historical writer.
Relevant evidence: Yes