Okay, to be honest, I've had depression. Not so much from a horrible event in my life, but rather a bad set of family genetics. So, with that said, I'm not quite sure what it's like to be in the depressive state from such a tramuatic event. However, I will tell you this, there is nothing you can do to help her besides encourage her to talk to the counselor. I suppose you could tell the therapist yourself, and risk losing your friend's trust in you. But only pursue that option if you think there is no other viable choice.