Yes, the girls didn't play their cards right all the time, but they also didn't always behave like squeamish weaklings either
Bobbie has a great plan to distract Zalman King, sort of pretending to like him so he'd be distracted.
Then later, she distracted the other brother so her classmate could untie the good guy. Pretty smart stuff there, and I like characters like that instead of just screaming.
The teacher also picked up a weapon and struck the final blow. She wasn't just a spectator; she was the ultimate hero. Good stuff.