I hear you, and I don’t have a view one way or the other about her guilt.
But this is the difficulty with probability. If I’m waiting at a bus stop at 08:30 every weekday morning and, over a year, 4 people collapse and die at that bus stop, people might accuse me of having something to do with it. Because I was at the bus stop every time it happened. But, I’m always at the bus stop, so of course I’ll be there if someone collapses and dies. Also, I wasn’t there for a 5th death, that happened at a weekend. But no one takes that one into account.
My understanding is most babies died on a night shift. Letby worked more night shifts than colleagues. She offered to cover extra shifts because she was conscientious and helpful. Otherwise, colleagues who had families would have to cover them. And she was young and saving up, so eager for the extra money. But night shifts were when the hospital was most understaffed. If they called for a doctor, they’d take ages to arrive.
This is the conundrum. Was she a murderer, who offered to work extra night shifts to take her chance to murder, when there were fewer people about? Or was she a helpful and conscientious nurse who was more likely to be working when very sick babies were more likely to die?