[@Melo] She must know about it fist hand or the knowledge about it must be unimpeachable. If she invokes the threefold unjustly, she will suffer its consequences. So I would imagine she would only use it for acts she is certain beyond shadow of a doubt are deserving of it. Lets say the further back an act goes, the more the certainty of it will fade, so she would avoid using it on past acts.