The narrator is Tita's grand-niece. What are the advantages and disadvantages of using such a narrator to tell the story?

Esperanza, who is Tita's niece, discovered her aunt's cookbook in the ruins of the De la Garza ranch. She recreated the recipes in her own home, and she passed down the family stories to her daughter. As a result, her daughter becomes the novel's narrator, incorporating her great-aunt's recipes, remedies, and experiences into one book. She justifies her narrative when she explains that Tita "will go on living as long as there is someone who cooks her recipes."