Again this is a Women's Fiction novel but also a Psychological Suspense. 

Loving wife and mother, Lexie Vaughan, stabs the husband she no longer trusts. Despite all evidence to the contrary, she must convince the police she had no choice. With the help of a reluctant cop and her brother in law she tries to make sense of events leading to her actions. But her husband is always one step ahead of her and if she doesn’t stay out of jail her son will be in danger.