Ah, I was quite sure that this is it. That scene of lightly "choking" her and doing it on the table in the main room, came from drinking the cure from flowers in the kitchen. I hope it's not a thing that has a cut off point, otherwise you might miss out on that scene. It's also possible that you might not have done all the conversations near the fireplace with Mia. Especially the ones pertaining to her taking on Robin's duties. And if it's not really that, then I have no idea at all. Good luck nonetheless.
Okay, so I booted up my game and went to the kitchen, made that tea and had an option to ask Mia for help. It leads to that scene I mentioned above. So it is THAT scene. You just need to find a way to unlock it. So yeah, getting through all the conversations options with her would be the first step and after that try making a cure again.