I have faced the dire and painful truth: Mirabelle's book was not working. I don't think it was a bad book, but it was too weird and difficult to get into for anyone who doesn't know the world intimately. It doesn't have the relatability of Penny's books. It doesn't have the same fun tone. For the book that branches out off of Penny to the rest of my supervillain world, I need the story to be as easy to get into as possible.
So I switched to Magenta's story. Here's chapter one of I'm Late For Alchemy Class. Good luck.
Oh, and the paperbacks are already out for Vanity Rose!