Castle Hangnail by Ursula Vernon

Castle Hangnail - Ursula Vernon

From the blurb:

"When Molly shows up on Castle Hangnail's doorstep to fill the vacancy for a wicked witch, the castle's minions are understandably dubious. After all, she is twelve years old, barely five feet tall, and quite polite. (The minions are used to tall, demanding evil sorceresses with razor-sharp cheekbones.) But the castle desperately needs a master or else the Board of Magic will decommission it, leaving all the minions without the home they love. So when Molly assures them she is quite wicked indeed (So wicked! REALLY wicked!) and begins completing the tasks required by the Board of Magic for approval, everyone feels hopeful. Unfortunately, it turns out that Molly has quite a few secrets, including the biggest one of all: that she isn't who she says she is."

This is an entertaining, charming and amusing children's fantasy novel, with adorable (and original) characters, but also manages to deal with some "grown-up" issues and social issues that may be encountered by any child.  Beautifully written, possibly "educational" without bludgeoning the reader over the head with it, and lovely illustrations by the author.