The title gives it away: "The Life before her eyes". Right before you die they say you see your life passing before you. She is actually the one who got shot and died not her friend. The movie tells you she had an abortion. She picked the baby name Emma with her friend which we saw in the little crosses. And the child in her life flash is also Emma and is always running away from her and she is searching in the woods for her, this represents her feeling of loss over the baby. Also her child tells her "you hate me". Which is her guilt for aborting the child, that the child would think she hated her that's why she aborted her, again her guilt. What we see in the whole movie is what passes through her mind the moment before she decides to sacrifice herself. She knows her friend is pure and she feels she is not. In her flash she shows you she feels she is a slut. She's very critical of herself like she is weighing her own value compared to her friends the whole time. The movie is what her life could have been. She was the woman with her husband only since it never happened because she died that day. it was her seeing herself which is the whole premise of the movie, her life passing before her eyes. You notice you never see the friend in her adult life. Also, she tells the woman at the memorial she is "not" one of the survivors. And her mother cries her name in anguish the moment she is shot. Mothers know this type of thing. Her mother knew it was her. I think it was very clear. There is no way a college professor is going to be with a 17 year old girl it was all her fantasy and proof this was just her life and what it could have been passing before her eyes while she made the decision to die so her friend could live.