This is a great topic and being discussed by Disney this week. Target was very impressive in Rogue one. In light of the sad loss of Carrie Fisher...
An article said that she was written for a big role in episode 9 confronting kylo Ren - her son who killed his father and Leia's husband. She is reunited with her brother Luke too.
The episode 8 scenes we're already finished. She will be in the movie in 2017 December. Pick up shots might be Sunita and CG.
Disney could decide to write Leia minimal or out of episode 9. My opinion is that to respect the character and a key scene of her confronting her son I would leave her in this and do it CGI.
Disney Cars 62 million-dollar life insurance payment that they had a policy on Carrie Fisher. They could afford the CGI. I think Billie Lord's wishes should be respected but she is in the movie and at least episode 8 ( her character not related to her real-life mothers.)
What do you think? Should they change what was planned for episode 9?