Is it ok to talk about things you would not talk about before meeting at least once or is there always that danger?  I guess this is an ediquite question as well.

After you have completed one session, she has been paid and you both leave, there is no reason you can't discuss anything you wish. The don't talk about it rule is so that you don't appear to be Law Enforcement. Once you have proven you are not, it shouldn't be a problem.