I think Luling seems more real as a character b/c she speaks coherently in her own language when she's telling the story (no more choppy english and miscommunications with her daughter), and she is again a coherent person herself (no confusion caused by altzheimer's).
the daughter discovers who her mom really was, and is, as a person, seperate from the mother identity that always seemed crazy and supersticious to her.
ruth always thought of her mother this way, and seeing her in a new light, where she sees her background and her superstitions come to make sense b/c she sees where they stem from, and just her mother's behavior and way of thinking in general, which is much more deep and complex than she realized (just by thinking of her as the crazy-ish chinese mother).