The act of apology also is an act of forgiveness for the apologizer -- the apologizer takes responsibility for the trespasses they have made against others and in doing so, unloads the weight of their emotional burdens and develops a better understanding of themselves. It is not an opportunity to make excuses for behavior. So I agree with everyone else in that it sounds like your wayward friend truly isn't apologizing. She probably has not dealt with the issues behind why she lashed out at you in the first place. If you did receive an actual apology, at that point you could consider whether this was a friendship worth pursuing again.
I ended a friendship with a woman following a heated battle of words between us that had been brewing for some time. Often I was hurt by her calous and rude behaviors over the years, but I'd let them go -- until I could no longer. Confronting her about her behavior resulted in a torrent of vile from her, to which I responded in kind. It was not pretty. I finally decided to take responsibility for my part of the disagreement and apologize to her. In forgiving her, I released the anxiety and pain inside of me and was able to forgive myself. However, there is no way I will ever reinstitute the friendship with her. Forgiveness, yes, but forgetting, no way.