That was going to be my suggestion - write her letters or emails that you just don't send. Stick the emails in a draft folder or something. Then, bring them with you to session.

Even though my T allows between session contact, and I do email her about once a week, I often have lots more that I want to tell her, but don't want to actually email to her. I tend to type out draft emails to T and then just save them off. I don't want to abuse her time with tons of emails, so I try to limit myself to actually sending just one or two between sessions. So, I keep a draft email going, and I just type my thoughts to her there, then save it off, and update as needed until my next session. Sometimes, I'll even imagine what my T might say in response to some of the things I've typed.