Unfamiliar magic

Desi is a witch, and at twelve she is old enough to be curious about what her mother keeps locked away. Reaching for the family spellbook when no one is watching, she sets off a chain of events she never planned. Among them, she comes face to face with the warlock father she has never known. She also forms an unlikely bond with Cat, a girl who once served her mother as a familiar, and the two grow close enough to feel like sisters.