I Shall Wear Midnight by Sir Terry Pratchett

As the witch of the Chalk Tiffany Aching performs the distinctly unglamorous work of caring for the needy. But someone or something is inciting fear generating dark thoughts and angry murmurs against witches. Aided by the tinybuttough Wee Free Men Tiffany faces a dire challenge for if she falls the whole Chalk falls with her . Paperback softback