Dear Irritated,
I can understand the situation you're in. Your friend is only acting this way because she is deeply hurt! She wanted you to stick with her during her tough time, and became very upset when you refused to be involved in the fight. She may be acting like she hates you but deep down, she also wants to be your friend, that's why she's doing this, maybe to get your attention. What I think you should do is confront your friend, you need to talk to her and ask her face-to-face why she is behaving like this. If you really want to be her friend, then tell her that although you really like her and want to be her friend, you do not like to be involved in arguments. It will make the situation way better and when she realizes you really want to be her friend, she'll want to be yours as well! But whatever happens, don't let your feelings get the best of you, what I mean is, no matter how much she annoys or ignores you, don't do the same to her because this will only make matters worse.
Sincerely,
Mr.Swag