[Xiyang]

Hi
Please help me find a fairytale.
When I was little, some over 25-30 years ago, I had a short story in a book.
It was a fairytale about a brother and a sister. The brother was ill. I remember more the book pictures, it was like when someone have a swelling in the neck, like a goiter.
The sister starts to search for a cure and she arrives at a lord/king (I don't remember what exactly it was but definitely a chief). From here I don't remember exactly what's happening. But the lord ask her to find a needle (most likely)/or a necklace in the sea/ocean. She finds it, and, as a reward, he is giving her a (magic?) pearl necklace, with whom she is curing her brother. After that, with that necklace she cures a lot of ill people who came to her.
I always thought that it was a chinese story, but from what I remember from the book drawings could have been a japanese one. The brother was shaved on top of the scalp, but I don't remember if the style was a manchu or a japanese one.
Does anyone know what i'm talking about?
Some parts of the story could be wrong because it has been a long time since I read it. But I would love to re-find it. At least to know the title.
Could someone help me?