I think we actually saw Addison before. I was re-watching the Chrismas special of season 5 and there was a scene of young girls teasing a deaf girl. The head of a group was this little mean girl who looked similar to Addison also the age fits. Do you think that it's possible that that was her? I don't think it means anything but it probably could since the Chrismas special was full of clues. What do you think?