IIRC, her score for psychopathy was very high. I think Demarte said something about that evaluation of the MMPI didn't have enough research done on it, so she didn't feel she could rightly include it (because it was unclear if it was reliable). Then, IIRC, JW asked her to go through those scores again, and she (JW) was on the brink of calling attention to the inordinately high psychopathy score. Demarte smirked and JW quickly moved on.
I'm thinking Demarte (and JM too) might not have wanted to depart from the Borderline diagnosis on the table, because it was a "known" element from the first trial and they wouldn't be surprised by any new tactics from the defense. In other words, the PT kind of knew what they'd be up against, and they already had practice! If they had inserted a new diagnosis this time around, there would have been a lot of unknowns about how the DT would handle it. What advantage would they have gained anyway by calling Jodi a psychopath?