Forgiveness in the glass castle book?

In The Glass Castle by Jeannette Walls, the underlying theme, itself, is forgiveness. Although both of her parents are clearly self-destructive and entirely selfish- her mother not selling her land in Texas and her father being an alcoholic- she overcomes their mistakes and moments of failure, and still learns to accept who they are as people. The book is just an account of examples from her childhood that present the argument to readers that even the worst people deserve forgiveness and it takes a good person to give it.

Hope that helps!