I completely agree with Valorum and Adamant when they say there are many candidates.
Adamant explains very well in what way each of them could be seen as cursed.
But I think the right one is Delphini.
Because of another clue:
The cover of the book shows a pic (also shown inside the book, on the website, and so on). It's kinfkind of the logo of this book.
And what is it? anAn Augurey. The bird, Delphini has a tattoo of. The bird of her guardian. Her nickname in her best-loved alternate reality.