I’m sorry she has to deal with this but it’s reality as you’ve noted and there’s some great suggestions here. I just want to say for the majority of us men who aren’t creeps, if you see a young woman being harassed step up and help. Even if you’re not a big, imposing guy, confrontational, know BJJ, etc., you can run interference with the aggressor.

“Hey, man, you look familiar. Don’t I know you from…”

“My man you dropped something back there”.

“Hey I’m not from here can you tell me how to get to xyz?

It may give her an opening to bounce and signal you know what’s up and are trying to help out.