I will stay on topic:
My pragmatic proposal would be to give her a CGI resurrection in EP IX and a death or unknown whereabouts in the first half of the movie. It will be 2019 by the time the movie comes out, people will not be as upset as they were if it happened next year. I would rather like to see some angry fans in 2019 than many confused people in the decades after the release, especially first-time viewers, maybe our kids. They will sit there and ask “But where is that General Leia from the last movie? Was she not in one imporant role?”. Better give a movie with one more CGI character to the next generations than an awkward excuse for a missing character or a plot hole. And maybe CGI will be better in 2018 (production time). Haven’t seen much of Tarkin from Rogue One yet, maybe it’s already good enough.
Provided her family agrees.

Or if they planned to keep the role as small or even smaller than in EP VII, disappearing through the plot (as suggested, for example in the crawl) might be feasible.

Maybe they are lucky and EP VIII already has such an ending that it can be instrumentalized for one or more deaths.