My best friend of 3 years was sexually assaulted recently. She told her boyfriend, who then told me. I’m not supposed to know about it, but I want to be there for her and help her get through it.
I don’t know how to do that if I’m not supposed to know. I’m also friends with her boyfriend and I don’t want to break his trust. Help!?!
LemonVibe 
What a horrible situation for everyone involved!
You’re in such a difficult position, knowing something like that when you’re not supposed to know. It’s a shame her boyfriend put you in that position, but I can also understand that it must’ve been a horrible thing for him to have to bear on his own.
I guess sometimes being a good friend and supporting someone through a tough time is just about being there in general, not necessarily just to talk about the actual trauma. Maybe the best you can do without ‘officially knowing’ is just being the best version of the friend you are usually. E.g making sure you spend time with her (unless she seems to need space), keeping in touch, doing practical helpful things,
being there so if she wants to open up, it’s as easy as possible.