The witch's parenting behaviour— after all she's done (locked Rapunzel in a tower, blinded Rapunzel's prince, tried to kill said prince, banished her to a desert/swamp), the script still takes note to mark her dialogue ("I was just trying to be a good mother.") as "defensive, yet sincere". It's hard to imagine how any one of her actions could be remotely construed as sincerely trying her best to be a good mother, until one takes a look at how the witch's own mother treats her. It was the witch's mother who raised the garden and threatened her with a curse if she ever lost the beans, even if they were stolen, which was by no means her fault. She's shown to be bitter towards her mother about this, but she never had any other example. She probably thought banishing to a desert/swamp (depending on the production) was just how most parents punished their children. Which also makes this Fridge Horror.
Analysis / Into the Woods