The Witch's Tears
fantasy, childrens

In a whirl of rainy weather, a strange woman appears on Theo and Dodie's doorstep making Theo very uneasy. His mother and little sister do not seem at all alarmed by her. Dodie loves Mrs Scarum's stories and her wild dancing. But Theo suspects there might be trouble afoot, not helped by the fact that his father, usually so reliable, has failed to return home. And when Theo is told that you can tell a witch because, if she cries, her tears will turn to crystal, he knows that Mrs Scarum is a witch. Or perhaps this time, tears will make things better?
Jenny Nimmo
Jenny Nimmo (born 1944) is a British author of children's books including many fantasy and adventure novels, chapter books, and picture books. Born in England, she has lived in Wales for most of forty years. Probably she is best known for two series of fantasy novels: The Magician Trilogy (1986 to 1989), contemporary stories rooted in Welsh myth, and Children of the Red King (2002 to 2010), featuring Charlie Bone and other magically endowed school children.
The Snow Spider, first of the Magician books, won the second annual Nestlé Smarties Book Prize and the 1987 Tir na n-Og Award as the year's best original-English-language book with "authentic Welsh background". The Stone Mouse was highly commended for the 1993 Carnegie Medal and several others of her books have been well-received or shortlisted for children's book awards.
Links
Official website.
Jenny Nimmo. Wikipedia.