I'm a bit surprised that Dr. Solomon didn't bring up JS's suggestion that a "bonus" be paid so she wouldn't have to go to jail (during her interrogation). Wouldn't that be a strong indication that she didn't comprehend the wrongfulness of her actions?
Also, she mentioned once, almost in passing, that JS seems to not understand that her children are not really dead (or, perhaps, that this understanding comes and goes). If I were her, I'd have reiterated that as an example of how JS floats in and out of a psychotic state.
Another point that no one's brought up yet - -JS talking about the squeaky chair when asked if she understands she can have a lawyer present (when read her Miranda rights).
I think the defense is dropping the ball.