Oh, Jen. You lying, cheating …
Well, hang on. How much do we really know about Jen as a character? After all, all we get is Judd's perspective on her, and he spends most of the book dissecting his own feelings and insecurities about Jen. Everything we see is filtered through Judd's perceptions and biases, and when it comes to Jen, bias is about all we have.
There's one question that keeps haunting Judd: why did Jen have an affair? Judd has plenty of things to blame: his sexual performance, Jen's beauty, Wade's predatory nature. Ultimately, he's just scared of the truth. The truth is that their marriage had been struggling for a long time, and Jen's affair was just the last nail in the coffin.
At the time of the affair, Jen was just as scared and confused about life as Judd. Her late-term miscarriage (their baby strangled on the umbilical cord three weeks before its due date) has a lot to do with that. But more important, it's Judd's reaction to the miscarriage that hurts her. It's well-established that Judd—and the Foxman family as a whole—has difficulty expressing emotion. She "needed to mourn" the baby, but Judd "acted like everything was fine" (31.52).
None of this means that Jen's affair was justified, but it does mean that Judd has to shoulder some of the blame. And, by the end of the novel, he finally does. He understands that he didn't do right by Jen. She certainly didn't do right by him, either. They both made mistakes, and now they both have to deal with the consequences.
The few times we get Jen's voice directly, she sounds, well, pretty forgivable. Let's look at two key statements:
(1) I am a flawed person. I was unhappy and did something inexcusable. But as much as you might hate me for ruining your life, playing the victim isn't really working out for you. (2.13)
Here, Jen owns up to what she did and then points out that, as wrong as she was, Judd isn't exactly an innocent victim. Seen in this light, she's not much worse than he is.
(2) I needed you to see me as your wife and all you could see was the failed mother. And now I need you to see me as the mother of your child, and all you can see is the failed wife. (31.64)
Ouch. If this is true—or if this is truly the way Jen thinks Judd sees her—then we're actually feeling pretty sorry for her. Believing that your husband sees you as a failure has to hurt, and it's almost understandable that she'd turn to someone who didn't—like Wade.
Thanks to moments like these, we can see Jen as she is: sensitive, caring, and deeply insecure. In fact, Judd shares these qualities with her. Maybe that's what brought these two wildly different people together in the first place. And maybe it will end up bringing them back.