My naked friend's pictures?

at gym class when we were changing in the locker room my bff admitted to not wearing a bra or underwear( i know that's a bit odd but she had a strapless shirt on and she was wearing a skirt and didn't want her panty lines to show i also know not the smartest idea) that day so i pinned a towel up and held it while she changed but one girl fell they domino'ed my bff fell pushed me down and was naked like shirtless in her under wear and some girl happened to be holding a digital camera at that moment and snapped tons of clear pictures of her naked body how do i help her keep them private as if it wasn't bad enough that thus embarrassing thing happened but currently she hasn't spread the pictures she just has them several of us told teachers but they just said what do you want me to do