It looks like my timing is odd--witch fiction happens to be a trend, and here I am writing it. I've read A Discovery of Witches, which is adult paranormal romance about a witch who's from a long line of witches, and now there's the YA novel Life's a Witch and its eventual series (http://www.publishersweekly.com/pw/by-topic/childrens/childrens-authors/article/50213-swamped-by-offers-self-pubbed-ya-author-gets-agent-and-more.html). I read Beautiful Creatures about a year ago, and that's also a YA witch novel.
Too bad my novel My Curious Adventures with a Witch isn't already published. On the bright side, my novella Witch's Familiar is available on Wormhole Electric's site. Furthermore, I'm about to get feedback on My Curious Adventures with a Witch, because I handed it over to Michelle, my former YA Publishing instructor, and she's about to give me the developmental edits that students did on the manuscript last term. So I'll soon revise it, probably share the revised version with my writers' critique group, revise some more, and start contacting agents. Then hopefully it'll get published before witch fiction goes out of style. I think many people have seen enough of vampires and are ready for something different, and I suspect witch fiction won't go out of style any time soon.