She could see the truth of everyone, read souls in a way that nobody else could. When someone opened up to her (which they didn’t always mean to do) she was greeted by a light and a dark wolf. They would fight viciously over which of them was the most honest. One was always stronger and better fed, but both would lose all the same.
Tired and defeated the light and dark wolves would step aside. Out would step a gray wolf. And that would be the truth.