Translations for prodigy in French

Here are paragraphs from public domain books translated:

She leapt from her seat. The key had turned in the lock. The count was coming, attracted by her cries. Yvonne glanced round for a weapon with which to defend herself. But the door was pushed back quickly and, astounded, as though the sight that presented itself before her eyes seemed to her the most inexplicable prodigy, she stammered:	D’un mouvement, elle se dressa. La clef venait de tourner dans la serrure. Attiré par ses cris, le comte allait apparaître. Du regard, Yvonne chercha une arme pour se défendre. Mais la porte fut poussée vivement, et, stupéfaite, comme si le spectacle qui s’offrait à ses yeux lui eût semblé le prodige le plus inexplicable, elle balbutia :
The Confessions of Arsene Lupin, by Maurice Leblanc	Les Confidences d’Arsène Lupin, de Maurice Leblanc