Notice how Mrs. Norris and Mr. Filch are so close? What if Mrs. Norris was once a human? What if they were both in love but wasn't able to be together. One day, some Mrs Norris asks some highly able students to help her turn into an animagus. But it went wrongly. Something happened so she couldn't turn back to human. They never spent their time apart whilst all this
They stay at Hogwarts hoping that one of the professors will figure something out to change her back, so they can finally be together.
