Fiction by Alafair Burke.
Now THIS is actually the "psychological thriller" it claimed to be.
It starts out with Angela, who is apparently standing by her husband, although he's being accused of some kind of assault. She's a tightly controlled character, hyper-focused on her son and her perfect homelife; it's not surprising at first how loyal she is to him, and what her reactions are. Still, as the story unfolds, we get more and more layers of information about her and her relationships and it gets really interesting. By the end, the story packed in so many surprises I was practically yelling WOW!
This is en exciting read!