That is indeed sad news.
She also contributed to ‘The Star Wars Portfolio’ (a book with art from Ralph McQuarrie), and the ‘The Star Wars Sketchbook’ (a book with art from Joe Johnston).
I think Carol was also the person that George Lucas dictated some of his concept / outline ideas on the Force and early Star Wars universe to for inclusion in the ‘Splinter Of The Mind’s Eye’ book, by Alan Dean Foster.