Perhaps the better question in domestic violence cases is not to ask her why she stays but to ask HIM why he HIT her in the first place. I seriously doubt that it was a case of self-defense, given the difference in their sizes.
Greatness lies not in being strong, but in the right use of strength - Henry Ward Beecher
Baby sister, I was born game and I intend to go out that way - Rooster Cogburn
"For what is Evil but Good-tortured by its own hunger and thirst?"
- Khalil Gibran