Really all that tough?
Brenda (and the other girls for that matter) really didn't seem to be all that bad-assed. They all basically talked big but that was it.
When Brenda had the shower room fight, all she did was stay on the opposite side of the shower for most of the "fight" and didn't really do much else. Same thing for the classroom fight, although she ripped the other girl's shirt off.
When her friend (Francine) came out of the bathroom and was grabbed by the Scars, she couldn't get away for the longest time. Pardon me, but she got all whiny and whimpery.
And at the end, Brenda almost gets knocked out when Jake swings the gate at her. Maybe it's just the era of the movie, but for a gang-like group of girls, they sure couldn't do much to protect themselves.
Goblin Cannonball: I hit something! Yes?!? No?!?