My gut reaction is to tell you not to give her anything to read at this point. I guess I am looking at it through my lens, but if I had given my XW a book with the word "Codependent" in the title during this ordeal she probably would not have taken it well at all.
Capitalize on what is good right now - and at the moment, it seems as if she is at least open to talking to you...laughing....joking. Hey, it's a start - and I am willing to bet (it your sitch is anything like mine) that is a lot more than you had 6-12 months ago.
I, too, had a tendency to crash through the door whenever I saw a slight positive. The sage vets around here would probably tell you to just play it cool....that is good advice. It seems like the LAST thing you want to do, but based off of my experience it is probably all for the best right now. Focus on the positives......you seem like you are doing well.
