The thing about Valente's writing is that she understands how to tell fairy tales and myths. Not that she retells fairy tales, but that she understands the language and style and levels of detail that go into telling such stories. She makes them work for her and makes language that would feel out of place or strange or overly lyrical work because she folds it into a larger narrative that is...evocative, but not quite like folklore.
In the Night Garden is one of her best works, a series of embedded and interlocking stories that unfold like a complicated puzzle-box, with each little twist revealing new possibilities and pushing against previous narratives. It's not a page turner, though each individual story is impossible to put down, but they have an Arabian Nights feel to them, both structurally and in the sense that you can't help but look forward to picking them up again.
Valente's language is polarizing, I think, which really just means that you either love the elaborate, poetic/folkloric flourishes in her style or find it distracting. That's a matter of taste but if her style fits your aesthetic, her stories are magnificent.