God @PlanDeRaccordement! There is another way of seeing all of that.
She had sleeping pills - couldn't take them for the purpose intended, to give her some sleep because she was the sole carer of her child
She loved him. Even in psychosis didn't want him to suffer so made up some weird, sensible only to her, plan to kill him in his sleep.
Only 2 people in the flat... because she was alone, his dad was elsewhere, all services withdrawn
His behaviours are consistent with the conditions he was diagnosed with! And there detailed information about how she killed him but no mention of other injuries. Do you think the DM would miss out on any salacious information?
It's fucking awful position for someone to be in and both of them deserve sympathy... but that doesn't mean condoning her actions. Just an understanding of the extent to which psychosis can change a person's thinking.
Save your wrath for the systemic failings...