All of the above, with #4 likely being the trigger.Which combination of those would ever lead you to kill multiple babies? Im not getting it.
From what we know so far, she was a long term, well qualified nurse who had been promoted up to the role she had and so far the killings all happened in a very short period around which she was having some sort of flirtation with the on-call senior doctor.
Now of course, plenty of people have crushes in colleagues and don’t go on to kill anyone to get their attention, but the overwhelming majority of people won’t have a personality disorder such as hers, so most likely it was a deadly combo of the 4.
Now if the police subsequently find out that she has killed many many more and from far earlier then of course all bets are off as to the cause.
As said though, in this case a deep and prolonged psychiatric evaluation/study should be in her immediate future.