Dont brush off evil as insanity. Most people arent insane when they do evil things. They are trying to escape consequences and chose to do evil things to do so. There is zero hint of her being insane, here.
I suspect for several reasons the baby was not born alive. I could be wrong, I’m not the ME that is just what I suspect.
If that be the case why did she put a dead baby in the closet? That is the question. Did she lose her mind over the baby being dead or is there another reason the baby was born dead?
You’re right.