Your child devoured The Land of Stories and came back asking for more. This is a shelf of books that do the same magic, real children tumbling into fairy tales, and old fairy tales cracked open and retold. If they loved The Land of Stories, any one of these will land. Pick by your child's age and by how much darkness they can take.
The Land of Stories works because it does two things at once: it drops real children into fairy tales, and it treats those old stories as a living world with its own rules. Every book here keeps at least one of those. Whatever After and Half Upon a Time are the funny, breezy ones; The Sisters Grimm adds a mystery to solve; The School for Good and Evil is the fat, twisty, boarding-school epic; The Girl Who Drank the Moon is the beautiful, deep one; and A Tale Dark & Grimm is the wild card, gorgeous and bloody. The one thing to steer by is your child, younger and tender toward the top of the list, older and hungrier for the dark toward the bottom. Magic and fairy-tale peril run through all of them by design. That's the genre a Land of Stories fan is asking for, not a warning.