By Joan Barthel. That's not narrowing it down a ton, subhed, so I'll just step in and note that the book is about the ordeal of Hope Masters. And that blurb from Thompson is...efficient?
The paperback's in good shape for 40 years old -- edge- and cornerwear, but the spine is uncracked, the pages slightly toned but clean (a couple, like the flyleaf, are a bit wavery).