There will be spoilers in this post!
you know, actually i'm ok with Kahvi dying. Wendy once said they thought about having Leetah actually save One-Eye but felt for the integrity of the story, they couldn't. It's like that now. True, Skot and Zhantee died in the Shards war and that was tragic but if Kahvi had another life-saving device now, it would seem a bit silly. Besides which, she's really old and she's lived a good life.