I think it's very touching that your T cried. It shows she cares. But should you protect her? Absolutely not. It's difficult for her, but probably extremely rewarding. Someone I know knew someone else who died of AIDS, and he said that it was one of the most impacting and touching things ever to walk through the death of that person with them. It is an extremely unique situation and your T will probably learn a lot and benefit from you being totally honest and open.

Oh, and I am sorry about the diagnosis. I can't imagine what that's like.