Better to let sleeping dogs lie. Or you will be apologizing for whatever part you had in the past incident, for the rest of your life. Your friend may even get some satisfaction out of reminding you that you ruined their friendship, and act like you owe her another apology, or even tell you to do this or that for her to show you are really sorry.
Some friendships aren't meant to last. Especially when it involves morals. She might even tell you that to prove your sincerity, you have to have sex with your boyfriend.
Do not participate in her sins, or place yourself in a position to be manipulated by guilt into doing something just as bad as she did.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.