is her meekness, IMO. Or should I say her meekness is powerful.

Definition of meek
1: enduring injury with patience and without resentment: Mild 1: gentle in nature or behavior
From http://www.merriam-webster.com/dictionary/

Or as Schindler explains it:
"Oskar Schindler: Power is when we have every justification to kill, and we don't.
Amon Goeth: You think that's power?
Oskar Schindler: That's what the Emperor said. A man steals something, he's brought in before the Emperor, he throws himself down on the ground. He begs for his life, he knows he's going to die. And the Emperor... pardons him. This worthless man, he lets him go.
Amon Goeth: I think you are drunk.
Oskar Schindler: That's power, Amon. That is power."
From “Schindler’s List”