Ex-Friends and facebook...?

I had a friend in High School that went on through out most of my college years. We stopped being friends when she accused me of being awkward around her fianc�e and not wanting to hang out with her any more. After she brought this to my attention (which I completely disagreed with, because I didn't/don't have a problem with him, I actually liked him for her and from my perspective we BOTH got busy with our own lives and just didn't put in the time for the friendship.) After a medium size blow up I invited her to a few things, all of which she turned down, and decided that if she really wanted to make a change in the friendship she would ask me to a few things. Well, that never happened. So we just lost touch. I definitely believe in the "you can go weeks, months or years without talking but true friends can just pick right up like it was yesterday" and from her actions I believe she doesn't believe in that. I decided to move on with my life, but she friend-ed me on facebook. I accepted at first and then de-friended her after it just weighted to heavily on how everything ended when ever I saw a comment from her. But the she re-friended me and we are now friends on facebook again. I am 6 1/2 months pregnant and it just hurts my heart when I see things from her and makes it impossible to move on because of the way things ended. I just found out that she is 5 1/2 months pregnant. And it makes me sad and sometimes angry when I see her talking to other mutual friends as well, (probably hormones) I don't want to wallow in this any more. Should I just de-friend her again, or should I send her a message explaining what my feelings are?