I'm glad that she's safe. The way you feel is only natural, I'm sure that in your position I'd feel the same. That said, you shouldn't take that approach in teaching self defence. Awareness and avoidance first, violence as a risky last resort.

There are many people who start training martial arts for self defence and go on to a lifetime of study. Imho, any reason to start is a good reason.
Self Defense
(Website by Marc MacYoung, not me)