Who was the narrator?

I'm sure you remember the scene where the orphaned little girl who whistled rather than speak was carried away and down the elevator as Elpidio tearfully watched. A young girl immediately came in and picked up a crucifix that the child had apparently dropped. Later, the adult Mariana wore the crucifix. Because I recognize the crucifix from the abandonment scene, I can only conclude that the child who was removed from the orphanage was Julia's, and that Mariana and Elpidio knew her when they were children.

Now, who was the narrator? I believe it was Julia's abandoned daughter. In the beginning, the narrator said something to the effect that she was going to bring happiness to the three people she loved by bringing them together. Who else would have known the three of them?

What happened to the little girl that was carried away? If it was indeed Julia's daughter, maybe she was dead, and manipulating the circumstances of her loved ones' lives from the other side... Any ideas or comments?