Gabriella Xavier was the last Queen of Camelot, and the daughter of King Alexander Xavier. When she was young, she fled Camelot with her grandmother during an assassination attempt that left her mother dead. They were both unknowingly saved by Salazar Slytherin and the other Hogwarts founders from an attack by a werewolf.
After turning 18, she would marry her friend Darrick (who was from a family of pot-makers), and bear a son, James (who she called her "Little Prince").
She is also a distant ancestor of Harry Potter and his children.
- Gabriella first appeared in the Christmas short-story, "Merlin's Gift," although she wasn't identified by name. Afterwards, she became the protagonist of the stand-alone book, Ruins of Camelot. She later made an appearance in James Potter and the Morrigan Web through the Mirror of Erised.
- Interestingly, her son shares the same name as her descendant, James Sirius Potter. Gabriella even admitted her delight with the name James.