the reason I asked my previous question is because, like they said, rape is a predatory action.
if she were already depressed and/or emotionally unstable (which isn't to say she was a nutcase - not claiming that), then she would be "easier prey" to the rapist - whether he knew it or not, or if there were subtle social cues that we don't even consciously see - the fact that they could have been there still exists.
all I'm getting at is that, while it sucks that your friend killed herself, it might not be because of the rape. the rape certainly wouldn't have helped anything, but both of those horrible things could have started by a much smaller fire that you were unaware of in the past - meaning she was depressed before.
it is hard to say whether or not that is the case since you already stated that "she seemed happy" - if she could fake it prior to killling herself, it is very feasible she was faking it all along.
depression is a mix of the wrong levels of neurotransmitters in the brain - if more people would look at it from the chemical causation standpoint and not seek physical actions that may have caused it, perhaps people would be more open to the fact that it is, if not normal, at least very common, and then the stigma can be removed from it and more people can get treatment sooner (especially since "later" isn't usually an option if they are suicidal).
and I speak with much experience in this.