So as we know most people think that Ali has a twin.
So in episode 13 or the Christmas special in a flashback Ali saw herself find two identical yellow dresses her mother made her say there was only one. Also Bethany and Alison knew each other well. Another reason is we found out that who was having an affair well mrs.dililaurentis and Bethany's dad right. By Emmagirl965 and gumdrop457
