Nona doesn't change the status quo, so her introduction and longevity in every chapter since her introduction is not needed. She's not "bad,' but she's not even a 'character' so far. She's only shown smug smirks, and her near grinding on Ted (another character who doesn't change or advance the plot, but his schtick has always been that he's super naive and takes Evan's word for fact 100% of the time, like every single other character in the series, as was mangas gimmick.) Nona is just the narrator box, but without the meta humor. If she had a real character/dialogue she'd be without problem.