Let's be clear, LW doesn't owe Jane shit. And normally I'd say "block her and good riddance" but I think that if LW was going to do that they would've already done that and not written in to an advice column. Similarly, I doubt they'll feel real good about themself if they email back "No, I don't forgive you, you hateful bitch, so fuck off and die already".

If LW has not blocked this woman then I suspect LW does care at least a little that she's upset, if only because it's important to LW's self-image to be a better person than Jane ever could be. LW would be justified in actually not caring a bit, absolutely, but I don't know that this is actually how they feel.

So, if LW is not willing to block and forget about it then I'd suggest they send a single email saying the following, with the parts in parentheses optional:

(Jane, you made me feel terrible every day for over a decade. I don't know why you did that, and I really don't want to know. I had to go through a lot of therapy to be sort of okay, and honestly, you should do the same thing. That's not a quick fix to make you feel better about yourself - nothing is going to do that. Even if I forgave you, that wouldn't make things better and I think you really do know that. Therapy might help you understand why you did those things and help keep you from doing that sort of thing in the future, and that might help you live with yourself.)

If you're serious about being sorry then you'll understand why I don't want to talk to you. Never contact me again. (I don't want to be forced to take legal action if you continue harassing me in this manner.)