The fact that you're worried about your friend and that you want to be there for her says so much good about you. I hope you do manage to call her. I know it's tough, but if you can, try not to focus on your speech. If you don't worry about it, she almost certainly won't either, and then she'll have space to talk about the things that are bothering her. At times like those, having a nonjudgmental friend who is willing to listen can mean the world.