Be You Friendly or Other?

I recently traveled with a close friend of mine of nine years to the site of her brother's death. He was in a deadly car wreck a year ago. Well, when we arrived we pulled over to the side of the road and got out and went to the tree that he hit. I felt cold chills and a feeling of dread while standing in the place he fell when he was ejected from the car. I called my friend over to see if she felt it too. She did. She got overwhelmed with sadness and started crying. I comforted her the best that I could. But as we were getting back in the car I looked back at the tree to thank him for communicating with us, however creepy it was, and I could see him and hear him telling me not to let her do anything stupid. I promised him that I would take care of her. We left and the song on the radio (not an iPod) was ACDC's Highway to Hell. His favorite song.
Then two days later I had woken up early to go to work. The day went well but I kept feeling a chill run down my spine. My friend called me shortly after I got off of work and asked me if I wanted to go to the reservoir and take a walk with her. I agreed to go with her. When I got there she went to the bathroom to get some warmer clothes on. When she came out she had a gun, and she gave me a note written on notebook paper. I didn't read it just put it in my pocket. She held the gun to her head and that was the end of nine years worth of friendship, sisterhood, even.
However, that is not the meaning of me posting this discussion topic. My real point is that I have a question... Do you think her brother was making her do it? Or maybe warning me? Or perhaps trying to make me stop her? What do you guys think?