If You Lived Here, by Dana Sachs (2007)
This book is so good, but it was also so sad. It's difficult to evaluate such a book after reading it: was the quality of the writing and story worth the number of times I wondered if life was worth living at all?
The story is told in alternating chapters by Shelley and Mai. Shelley is trying to adopt a child despite the effect it's having on her marriage, and Mai left Vietnam decades ago under extremely sad circumstances. Shelley and Mai become friends, and their friendship is instrumental in changing the outcome of these stories. Nothing ends up super-happy, but both women are happier at the end than they were at the beginning.
I can't stand stories about sad things happening to children, and so I will warn you that something very sad happens to a child. The book doesn't dwell on it--but I did, afterward.