Em este site , você pode ler isso (enfatiza o meu):
In a trance-like state, the Na'vi and Mo'at prayed in the hope that Eywa would permanently transfer Grace's consciousness to her avatar body. Unfortunately, she succumbed to her wound, but before she passed away, Grace told Jake that she was with Eywa.
Então ela realmente morreu antes da cerimónia estar completa, mas sua consciência sobreviveu e agora vive dentro de Eywa.