Overview
"Brother and Sister" is a Greek fairy tale collected by Georgios A. Megas in Folktales of Greece.
It is Aarne-Thompson type 403A, The Wishes.
Synopsis
A brother and sister were poor. Once, when work let the brother buy some sardines, he gave them to his sister to keep for their evening meal. Later, three women came to their house and asked to rest. And the sister let them in and gave them the sardines. And the women told her that when she combed her hair, pearls would fall from it; when she washed her hands, the basin would fill with fish; when she dried her hands, the towel would fill with flowers. Thus, was she able to give her brother mullet rather than sardines. He demanded to know how she had gotten it, but was pleased once she told him. So he went to sell the pearls, but he was hauled before the king because it was believed that he had stolen the pearls. So he told the king his story, and the king resolved to marry his sister.
From Wikipedia (CC BY-SA 4.0).