It's hard to say if realization will kick in. I've witnessed my mother's intense guilt over an abortion for thirty years.
Ms. (for "monster") Yates will have to work hard to not remember Luke, John, Noah, Paul, and Mary.
I agree with you: I think it will hit her at some point, though she must be blocking it out presently just to survive. I don't read her as an across-the-board psycho devoid of all conscience. I think she was twisted inside by a variety of conflicts and that rage (directed towards???) was an integral part of her ability to carry out FIVE drownings.
She deserved the death penalty for what she DID. Period. Motivation may interest the psychiatrist, but action interests the law. Or it used to.