On the other hand, my dad was shocked that it put his Crohn's into remission (which I guess is a thing doctors all know -- chemo would be a great treatment for all auto-immune diseases, if only it weren't, you know, chemo), so for him, the last years of his life he was able to eat for pleasure for the first time in a decade.

(Not diminishing how shitty this was for your sister, mostly just piling on how hella weird chemo is.)