Like all anthologies, this was difficult for me to rate because it was all over the map in terms of enjoyment for me.
Some standouts both good and bad:
I really liked Delia Sherman's titular "Queen Victoria's Book of Spells", which was both an interesting story and a magical world that I would enjoy reading more of.
"Phosphorus" made a deep impression on me as both an explicitly didactic story about Lucifer matches, "phossy jaw" and the match factory workers' strike and a creepy story about love, magic and sacrifice.
Cat Valente's story about the young Brontë siblings, "Without Us Were Shadows", is clever and bittersweet, and I especially like the relationship between Charlotte and Branwell.
"Estella Saves the Village" is a delightful story by Theodora Goss about rescuing beleaguered characters with a massive crossover fix-it fic that takes on an existence of its own.
I was super disappointed by Ellen Kushner and Caroline Stevermer's collaborative effort, "The Vital Importance of the Superficial". They wrote it by exchanging letters because Kushner was looking to break some writer's block, and I think it should have been rewritten after they figured out what it was going to be about or just stuck in a drawer as a writing exercise.
Elizabeth Wein's "For the Briar Rose" is exquisitely researched and footnoted, but basically nothing happens in it.
Geoffrey Maguire has written some of the most bizarre A Christmas Carol fanfiction I have ever encountered. Have you ever wondered what would happen if Scrooge had had children whom he neglected because he was too busy distributing charity? Probably not, and "A Few Twigs He Left Behind" is unlikely to increase your level of interest in the matter.