It's not really a twist for me, it's easily guessable. MC doesn't have any interest development in the duke at all, she has more chemistry with Jade since author kinda ignore the duke relationship with her, so I'm not really surprise. In contrary I'll be surprised if she's the duchess. I was guessing it was Rina or Clarise, though I prefer Clarise. But when they said red rose is the proof, it's immediately known that Rina it is. It's definitely not MC, the only other one can touch it is Rina.