I have watched it twice and knew it.Watched MAMA,
The women fell from the cliff along with its baby and its spirit searched the entire forest without knowing what happened to the infant. While doing so it came across the sisters hiding in the cabinet and looked after them.
The younger one is more attached to the spirit hence it took.
But spirit ,do you believe in it?
If it were a bollywood film,all would have critisized the director for superstitious.