Let it go. say silent prayers for her.
I lived in a small town, if you do nothing small town people will MAKE UP stories about you, just to have something to talk about.
ignore it.
if she wants to file charges offer to be a support. if not just let it heal. someone should get that kid into counseling.
i was raped then assaulted by my ex fiance, it got nowhere in prosecution and then he turned it all against me to try to hurt me and intimidate me to stop prosecution of him for the rape and assault. he wanted to avoid exposure of what he had done. it was a nightmare.
rape is ugly. i learned defense and security and now do not trust even a close male friend around unless we are in a group.