Red as Blood by Tanith Lee.
From The Penguin Book of Modern Fantasy by Women, edited by A. Susan Williams and Richard Glyn Jones, Penguin, 1995.
A retelling of Snow White with a unique twist. The Witch Queen is deeply religious and is concerned about Bianca, daughter of the first queen. Bianca does not like mirrors, in fact, the Queen’s magic mirror does not even see Bianca. Binca will not accept a golden crucifix nor will she walk among white roses. There is huntsman, and seven dwarfs and, in the end, a prince riding a white horse.
This tale is strange, dark and very well written. Find it if you can.