I agree with OP. I did not like the book . I found parts of the story disingenuous, particularly the details from her very early childhood. It has been a while since I read, but recall becoming very annoyed with the author by the time she had moved to Arizona in the story. Too much self congratulation. Overall I felt unfulfilled after reading and like it was a waste of my time. Contrast that with the Frank McCourt memoir, which I think was genius.

OP here, still pissed I got the title wrong in my fast typing in between meetings.

Anyway, it helped that I looked up some more recent interviews - for fans thought I'd post them here.

Here's a Q&A she did back in 2005 (so soon after the book was published) to accompany a Nightline special:
http://abcnews.go.com/Primetime/Entertainment/story?id=552776&page=1

And here's a 2013 interview with the NY Times Mag that includes a pic of her mother! And some updates.
http://www.nytimes.com/2013/05/26/magazine/how-jeannette-walls-spins-good-stories-out-of-bad-memories.html?_r=0

I don't like most memoirs, but loved The Glass Castle, as did my mom. I think it's Walls's writing--she doesn't wallow in self-pity or try to overdramatize things. She tells the story in a straightforward, strong way, letting the facts speak for themselves.