Agree.
Also - people are not responsible for their looks or voices, but NK has surprizingly scratchy voice.
The manner of speaking is unusual. Overproductive, to be polite. This whole interview would take perhaps one hour if she answered to the point, but I find all these excursions into her macronutrients, her exercises, her plants, her apartment, her habits, etc is horribly annoying. She comes across as very self-conceited and really, not caring about anyone or anything save for herself. As a stepmother, she would have been obstinate, rigid and boring. MOO.
Also, she was interviewed by the police. And given what we know now about deleted texts, and other lies, how can we believe her statement "I am totally honest with you guys"? I don't find her honest, and I think that maybe her logorrhea had to do with anxiety caused by unwillingness to answer some direct questions that the interviewer asked her. A glib, but boring, liar.
But at the same time, I don't feel that NK is in any way involved or implicated in the annihilation of the family. She comes across as pretty smart and a good planner. (She also appears bitter because of personal problems, maybe not only current ones).
I can't imagine NK "coaching" CW on resolving his family issues. I can imagine her telling him that three kids and a divorce would be a huge financial burden for her to bear, and him deciding to cut the Gordian knot the way he saw fit, but it is not her fault.
(On a side note - i really liked the interviewing style of the detective).
Her dad is pretty angry when he says "leading", but when they discussed her friends between the two, they both appeared viscous, I can't find a better word. Rolling back and forth for how long you need to know a guy to introduce him to your family, all these meaningless repeats...