You know, it's a difference if you're confronted with a persons death or if he get him arrested. I think it was her seeing him getting his last meal, him being sentenced to death and almost being killed there.
The blackmailing could come every second... No, she isn't doing it yet but I can see her changing her mind at any point.
Her attitude about being smarter than everybody is bothering me so damn much because it simply isn't true. She doesn't even know the whole story but is fooled into thinking she does