why is mama elena unable to produce milk? to whom does she give tita instead?

During Tita’s second year of life, her father suffers a heart attack and dies. Consequently, Tita’s shocked and grief-stricken mother Elena can no longer produce breast milk to nourish her child. Overwhelmed by her sadness and her responsibilities caring for the ranch, Tita’s mother passes her caretaking duties on to Nacha.