Diary of a Fairy Godmother by Esme Raji Codell

Hunky Dory is a model student. She can "make flowers droop like wet spaghetti" and "thunder rumble like a whale's bellyache" and has "a cantankerous cackle that rattles the bones of any vertebrate for miles around!" Hey, when you're a student at Miss Harbinger's Charm School for Young Witches and your mother wishes for you to be the "wickedest witch wherever the four winds blow," then these are the sorts of things that get attention!

Once, during a spelling test, Hunky shows she can spell dragon by turning a prince into one, complete with emerald scales and lovely fiery breath. He even swings his tail and destroys the back wall of the school. After some well deserved praise from Miss Harbinger, all the girls stuck out their tongues at her in tribute. Of course Hunky was moved by their jealousy.

And so it goes with Hunky Dory and her classmates Frantic Search, Twisted Ankle, and Acid Reflux...just to name a few. Hunky even turns princes into frogs, but there's one major concern. She always changes them back.

Actions such as this probably disqualify one from being considered the wickedest.

After a guest speaker, Hunky decides on a career path. Entrepreneur. Small business owner. But where...?

While traveling to a castle to see a new baby, and bless it with some form of witchy badness, Auntie Malice tells Hunky about F.G.s. They're nincompoops. Show-offs. They're Fairy Godmothers! Why, why, would anyone do...[shudder]...good? They grant...ugh!...wishes! Witches, on the other hand, perform mischief. Now that's something worth doing.

Some time later, the solution to Hunky's entrepreneurial endeavors presents itself in the form of an abandoned shanty with a well out front. Since Hunky has always pleased her mother with her rebelliousness, and since F.G.s are such nasty creatures, Hunky hunkers down in the well and, for a fee - one gold coin - she grants wishes. Sometimes even good ones. Why, she's acting like...like...like one of them!

What a story! A girl desires to be good, which to her mother is bad, but her mother desires her to be wicked, and what's more wicked than being good? (Good question.)