BBM
The other lawyers may disagree but I seriously doubt a judge would ever allow these texts to be introduced in a criminal trial. At best they show that a month after his disappearance, and during the portions of these exchanges that we are shown, Terri was not so concerned about Kyron that it prevented her from acting inappropriately. That's pretty weak in terms of probative value (proving her guilt in Kyron's disappearance). Weighed against the prejudicial effect (incredibly strong as evidenced by the posts in this thread) and the fact that she was under the influence of alcohol, it would probably be reversible error to allow the jury to see these.
Of course, Kaine got them out in the media for potential witnesses and jurors to see anyway.