
It could be really emotional and good story writing if in her final moments the spells and evil and manipulation snaps away and she has one brief second of being who she was suppose to be, a very loving mother to her daughter, and is crushed with the overwhelming guilt of what she's done before she dies.

The evil force, which I assume was originally in the box before consuming the boy and taking over his body, was already poisoning Josephine's mind before Letica was even born. Pushing her to only love her son, then, when the boy was fully broken the evil force became her son, having complete control over her.
Damn if we get some kind of redemption arc for Josephine... She might be controlled, but even so I can't imagine her becoming loving mother for Leticia, after all those chapter of hating her, it would be weird if FL forgives her.