It's also even worse than described; the school didn't even look at the Instagram post before disciplining her, relying only on (false) rumors that other students had spread about the content. The three students who were offended by the post and first complained to the school *also* had never seen the post, having only been offended by hearing the same false rumors.
Out of curiosity I looked into the Spence School incident, and it appears that the parents did sue the school.
https://casetext.com/case/parker-v-trs-of-spence-sch-inc
It's also even worse than described; the school didn't even look at the Instagram post before disciplining her, relying only on (false) rumors that other students had spread about the content. The three students who were offended by the post and first complained to the school *also* had never seen the post, having only been offended by hearing the same false rumors.