
From the very beginning, I always felt that the the duke fell for her way too easily. He has to experience a bit of hardship from his end in order to be 100% sure that he is in love with her.

I agree with that.
Because sometimes you don't know you love someone and care for them until there's a possibility that they won't be there anymore.
And yes she may be a little hard on him but from the way I see it I don't think he would be able to express his love to her or realize how much she actually needs and loves her without her doing this.
Please tell me that the supposed ml didn't actually murder her parents??? oh hell no what is this??? she has to marry her parent's murderer and on top of that she's still a child????????????