Madam Bones (and Harry and Arthur) walked somewhere else in the Ministry building; Madam Bones found out there that Dumbledore was declared to be Harry’s magical guardian during a special session of the Wizengamot in 1981—a special session that was notable for having just enough seat-holders to make up a quorum. And why did the Wizengamot need to appoint Harry’s magical guardian? Because the Potter parents’ wills had been ordered sealed by the Chief Warlock—Albus Dumbledore.