I think the basis of the argument is how can you forget your child
for SEVERAL hours?!?! One or two I can understand if you are preoccupied, but four or SEVEN???

The child does NOT cross your mind for
seven hours and needs to be found by someone else?
How can a mother, as in the OP story, not remember TWICE, that she didn't put her child to bed, to be able to say, "The child is sleeping."
How could, in the other example a PP posted, that teacher leave her child in her car for SEVEN hours, not think of it once??? Not get an inkling, that something is off, for seven hours?
I saw her story on Oprah, how she was wailing away at the police station. She could just have been a more convincing Susan Smith.
And no, I do NOT think ALL these cases are perfect murders. But, one or two people, who just did not want their infant anymore, could just wait till the perfect hot day in summer, and bake their child to death and wail convincingly about it after. Meryl Streep is not the only one who can cry on cue. Murder ONE
is premeditated murder.
Then my child would be toast.

Whenever I can, I purposely leave my bag in the car, when possible, as I know I will be carrying packages back out with me, from the store.