To my knowledge her mother is actually obsessed with the sisters mom, and because the mother died then the obsession passed on to the sister.This story brings so much sadness, but it is done so well.
Is this with the mother the same as what is happening with the fiancé? Where her mother does care for her, but because of some external factor/force controlling everything cannot speak those words OR show affection to her? Or did her mother actually never love her even a tiny bit?