why is nancha able to relate to tita more than the other girls?

After Tita's father's death, her mother, no longer able to care for her because of her grief, passed her caretaking duties on to Nacha. Under Nacha’s care Tita becomes almost inseparable from the setting and routine of the kitchen. Nacha took care of Tita like her own child from the time of her infancy. Thus, she related to Tita more than the other girls.