Possibly the worst thing I've ever done

Anyone seen the movie “Flatliners”? As a kid, we teased a girl who later suicided. When I was 12-14, (seventh-eigth grade) there was a girl in our class who was generally unpopular. She was a bit shy and basically quite unattractive. I was also having social problems at the time, and our school was very cliquey - you were either “in” or “out”. I was on the borderline at that point. Anyway, at some point, probably in eigth grade, I made up the nickname “Frieda” for this girl. It was based on the Aussie movie “Puberty Blues” where there is a character called “Frieda the Moll” who is generally disliked but has sex with all the guys. I was being a smart-arse and trying to get myself ahead by treading on those weaker than me, which I know is despicable (there may have been an element of that even in the nickname - when you watch the movie, you feel a lot of sympathy for Frieda and despise those who mock her). Anyway, the most popular girl in the class picked up on the name and encouraged others to tease her with it. I didn’t do much of the teasing, but I certainly was reponsible in having coined the name. At the end of eighth grade the girl left our school. Her brother was in the year below us at our school, and I guess I heard of her now and again. It doesn’t seem she fared that much better socially at her new school. A couple of years later (at the end of tenth grade), we heard that she had jumped off a cliff. Most of us were overseas on a school trip, so we only got the details later when we came back. There were rumours that her Dad always gave her a hard time, calling her ugly and useless and perhaps physically abusing her. I have no way of knowing if that is in the least bit true. Because I was o/s, I missed the funeral etc. and I have always felt that I have at the very least some contributary responsibility to her death. I don’t actually expect forgiveness, as those I need to ask it from are her and her family, and because death is so final, forgiveness is not really an option. I guess I will just always feel terrible about this, and so I should.