In the moment, with everyone and everthing going on around her, I doubt she was thinking rationally or even knew that torching a car would be a long prison sentence. (if someone asked me before reading this article, I would have assumed a large fine + some community service maybe; then again I am not American so I have no idea how sentences compare).
"Everyone else was doing it" didn't fly with my mom, and probably won't get a pass from Judge Wapner, either.
Which is the logic behind Qualified Immunity.