This is a great thread!
I was so convinced going into T that I was going to deal with my SI until I'm 18 and then tell her, just so she couldn't tell my parents. Well...I realized that I couldn't deal with it on my own for any longer, so I sucked it up and told her..

That is, in my opinion, my biggest accomplishment, and my greatest progress in T. And I'm glad now that I did, because I feel like T and I are so much closer after that, and I have so much trust in her after the way she handled the situation.