Nah, I'll use my power called, "denial"
It has worked wonders for many years. For all I know, it was a tragedy and our guy received a letter she prepared beforehand. Like a secret letter that's unbeknownst to the viewers and it could only be given when he lives to old age to give him a little reward for not going off the easy way and repent thru saving lives.
Yes. That's actually the real ending, I didn't read anything else. It was a tragedy and deserves it's spot as a tragedy

Yeah, could be some metaphor shit. I don't believe that she's alive and even got her own paycheck? Nah. It was a heart disease that got her coughing blood that means the damage has been done to her heart repeatedly, modern medicine like digoxin idk (not a doctor, I can't prescribe) would alleviate the symptom but fully curing it is out of the question.
Tips of her fingers turning purple could be because blood circulation isn't circulating enough. Plus, multiple panels have shown people griveing for her. She cannot be not dead. So what was that about her writing letters that won't reach him? I don't... Wtf. It doesn't even have extras