I agree. I don't think the author is trying to justify Rio's actions. By giving Rio story some depth, we can see where it went all wrong.
I like to believe that at the end of the day, we take something from these stories with us. So we can learn from mistakes we didn't make. For example, in this chapter Rio had the chance to say "well, actually my husband..." and get her friends' inputs. Now, I understand this is a huge hurdle that takes a lot of trust and risks, but... Life has never been easy, and facing it alone is a hell of a challenge.