I too would love to know when as well as where - was she still living in the shack, or had she moved out of the mountains and into assisted living or in with one of her children?
This book seems like it was home-typed and self-published rather than typeset. If 1971 wasn't a typo, it would have been very hard to add any words except at the very end of a chapter.
By the way, I've never seen hyphenation like this before, where the hyphen can show up either at the end of the line or the beginning of the next. For me that really made for a jarring read!
The 1971 question might be cleared up if anyone knows where "The Big Hill" (p.20) was/is today. Could that be the road my GPS insists on taking me on, to the right off Bowen Rd maybe halfway between Ocotillo and the ranch (when driving towards the ranch)? That road is a fenced off path now.