Trilogy Involving Magic Book and Twin Teenagers

I remember reading this trilogy in elementary or middle school but cannot find it despite numerous google searches, apologies for the very little details
I remember this from the first book: There's twin teenagers who live mostly on their own because their dad has a travelling job and their mom is gone. The boy has dyslexia and I think the girl wants to join their dad in his job, selling books? Their dad comes home from a trip and visits local bookstore, one of them hides nearby and listens to the meeting. The bookstore owner brainwashes their dad with some magic phrase but it doesn't work on the kids, they later discover that it's because they're too young for the magic to work on them. I don't remember a lot of the plot inside the book, I know there's a scene where one of them runs to a park to escape evil guy and hides in some bushes, but at the end the bookstore owner ends up using a spell to see through the dyslexic boy's eyes because he can read the book because the letters in book are always shifting and moving, and his dyslexia makes it so he can read it. The bookstore burns down, evil bookstore owner dies
I don't remember a lot of the rest of the plot but at the end it turns out that their dad was Adam and a worker at their local retirement center was Eve. They burn the book so that the magic can't be used by other people, but discover that burning the book broke the magic for them too and they can't use it anymore.
I think the girl uses a lot of transformation magic and often disguises herself as other people? I'm sorry for not remembering more details