The Chosen One had correctly surmised that a consultation with Hermione and her analytical mind was in order, regarding the question of guardianship. Of course, she would have a book on matters of wizarding family law with her – he didn't bother to ask from where she had procured the tome, because at this point, nothing surprised him with Hermione anymore, despite her amusement at a continued tone of surprise at her brilliance, particularly from Ron.