Unfortunately any motive may not conform to our perception of rationality if her mind was seriously unbalanced. If she was fearful of losing her children and harboured any "irrational" beliefs maybe fueled by a religious upbringing, then her possible choices would seem ridiculous to us, but make perfect sense to her.
I think I am most on the fence about this case because of the impossible choices we have about accepting the dark side of human nature. I don't want to believe that JB could cold bloodedly slaughter his family and stage aspects of the scene, purely for money, but it happens. Nor do I want to think that his sister did it because of mental illness, because most people suffering mentally are a bigger danger to themselves than anyone else, yet we wouldn't have a verdict of "not guilty by readon of insanity" or "diminished responsibility" enshrined in law if it didn't have precedence.
I also don't want to believe that law enforcement would do things that actively interferes with establishing the objective truth about a tragic case like this, yet there is substantial precedence for that in other cases. I'm not denying how hard a job it is, or how frustrating for those working in it who see clearly guilty people get off on technicalities.
Our system is adversarial and once a case is in the courts domain unfortunately it's framed as a fight to win. I haven't been involved in criminal oroceedibgs, but I had a taste of the "family courts" where the "balance of probabilities" is the frighteningly nebulous standard applied and my solicitor told me then that hoping for the truth was impossibly naive. In the Lucy Letby case it does seem this latter standard was somehow elevated over "beyond reasonable doubt" . In either sort of court proceedings, given the severity of the consequences, standards of evidence and procedure needvto be scrupulously upheld, otherwise we have situations like this more and more, with possibly innocent people being convicted then having to keep tying up the system with appeal after appeal etc.
As I say, I'm on the fence with JB mainly because of all the factors mentioned above and because I wasn't there and I have a lack of faith in the system, which is on me.