It can be hard risking when you like your T so much. I too get worried that I'll be cast off if I 'bug' them too much. Usually, when it's brought up, they will give you guidance on what is ok and what is not. Since you haven't discussed it yet, I'm sure she won't be angry even if you did go a little overboard - but it doesn't sound like you have to me. I especially think the letter is a good idea and a good step forward in therapy.