I love the idea of a blog for just you and T. When you say you sent her a message on the net, do you mean you made a blog entry or sent her an email? When you said you didn't want to express strong feelings on the net, did you mean you didn't want to communicate by blog/email or that you wish you didn't have these strong feelings that you couldn't contain until your session? (If it is the latter, it sounds like your T is providing the blog to help relieve that. If it doesn't help you, you can let her know and not do it anymore. And you can ask her for ideas for other forms of relief, such as writing in a journal.)

If it were me, I would want to know what security measures were in place on the blog so that I could be sure it was accessible only to me and her. I wouldn't want anyone else to be able to find it by accident or have it come up in a google search. Is it password protected?