Nearly seventy hours of narration sit behind a single listing here, because The Witch Between Worlds arrives as a complete box set rather than as separate volumes. That format is the most useful thing to understand about how Emma Glass works: the story is conceived as a long run from the outset, not as a novel with sequels bolted on afterwards.
The catalogue files it with teen and young adult fiction, while the title declares epic fantasy, and both readings are defensible. Series built at this scale tend to attract listeners who want somewhere to live for a few months rather than a single weekend, and this one is constructed for exactly that appetite.