Now, I'm just wondering... do I even bother with this, you guys?
Interesting post. I like the fact that in spite of everything, as passionate as she comes across, she can still sustain a conversation with you. That shows at least some sense on her part.
If it was me, I'd consider the conversation that you had about blood transfusions, completely ignoring (or most of it) the content of the email in the other matter. The reason I'd do that is that I'd agree with her about the fact that there are dangers in blood transfusions, and that there are truths about what many medical professionals say in terms of being cautions, and everything else that is relevant.
I think that some JWs need to see that outsiders are not the monsters that they are made to be, and that we can be reasonable, and we don't need to be anti-them.
Then in later conversations I'd address anything else if at all. Personally I have no interest in convincing, saving or converting anyone of/to anything, but that's how I'd address it if I did.