Good heavens, Mrs. Meade. Remember yourself.
I don't know what that means, but the reason why I suspect that Rowling's inspiration has come through channeling is because, although the novels are pedestrian, they have enjoyed unprecedented popularity with children, while serving to normalize the occult. The books are a perfect, imperfect storm.
Channeling has been associated with other malevolent cultural phenomena, like Madame Blavatsky's founding of the Theosophical Society.