Correct - her original origin of being saved from a burning building is now in canon per the Artemis: Wanted one-shot.
Regarding Donna's original origin story: The iconic 1984's New Teen Titans #38 "Who is Donna Troy" by George Perez and Marv Wolfman is such a great read. It reads more like a mystery with Dick/Robin finding clues to uncover Donna's mysterious past.