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 Francesca of Savoy"): She was a sister of Umberto II of Italy and of Queen Giovanna of Bulgaria.
Relevant evidence: No