Generally speaking, if it was making a movie, and Firefly came out like this, then she was definitely doing the right thing. However, this was a kingdom, and those soldiers looked like they were trying to enforce the law, so without knowing the context, jumping out to save the girl, was a very foolish thing to do.
Jack the mouse knew this. Who knows whether the blonde swordswoman was a good person or a bad person? Just because she was being attacked by a dozen men, does it mean that she was a victim?
There were so many games, in which the heroes not only took all kinds of red and blue potions dastardly, but they also took turns to wear the boss out, and no one would say the boss was a good person, and then jump out to destroy the hero's group.