The best way to avoid THAT pain is to shut them out of your life before they have a chance to shut YOU out.
I agree. She is distancing herself from anyone who could hurt her feelings by not believing her. I think that's what Casey is doing right now, and she doesn't want to answer any more questions either, specially not from family. There's a time to fess up and hers will come only when she is ready - maybe it won't come at all, depending on the extent of her pride. Nobody can "make" her talk but herself.
Admitting to a lie (specially admitting to many lies on such an important subject as the life of a daughter) will destroy any "image" she had of herself, will destroy her pride, and will be the ultimate blow to her self-confidence. How she'll get there.....I don't know. She has driven this way too far, told way too many lies....
Maybe there is a little bit of shame in her somewhere, just enough of a tiny bit to not want to see the pain in her family's eyes anymore (coward), yet she is still not able to tear down her own false image, an image that only SHE holds of herself. She probably doesn't know what to do to help her present situation and hopes that if she holds on long enough, and remains :silenced: , it will all go away.
I'm no psychologist but the annihilation of your own self as you know it, is quite a daunting task. To start fresh when there is nothing left but life in prison and possibly the DP, is definitely not an enticement to spill the beans. I don't think Casey knows what an "un-guilty conscience" feels like.
Sorry about all this psychobabble, I was more or less thinking aloud.