Three Witches by Paula Jolin is the typical high-school-girls-form-a-coven-and-think-they're-witches with a twist: the girls are Muslim, Trinidadian, and Japanese, and their "witchy" cultural traditions are reflected in the book.
That being said, it was another teenage witch book. Not really my cup of tea (I prefer true fantasy, not the "let's gather the materials to conjure the dead" kind). But I read it, and I promptly dedicated it to the public library. There are plenty of teenage girls who love this kind of thing.