She.... Should know by now that.. Whatever she does, only gain his nothing.
She.... Should understand by now that.. He acknowledged her nothing.
She.... Would walk away by now..
As he doesn't appreciate her like how she hold dear to his heart.
But she would like to think, to hope, to see changes in him. Because she knows what is he capable of. She trust him & know his strengths.
So she chose to believe him. Believe him still.