I would just take my cues from her. If she wants to reminisce then go for it, if she is frightened about what is to come - then comfort her, etc.
Just remember she is your friend and go in treating her as such - not like she were a china doll or a stranger that you had never met. And try not to be the first to start crying. I realize that may be difficult, but you don't want to put her in the position of comforting you.
My prayers and condolences go with you.