On the show bible,on Paper's part, it shows that Paper has three siblings: Sandpaper, which was seen in the actual show,and two siblings who never appeared on the show: Toiletpaper and Paper-mache
According to that,it says that Toiletpaper is a stand-up comic famous for her toilet humor,and Paper-mache, who's a snobby artist working in France
And i think Toiletpaper's role was passed to Potato in the final show (Because on her debut episode Potato was a stand-up comedy,expect the toilet humor part)