So she’s working with the Emperor as an advisor

I’m pretty sure that whenever he mentions it, Marie isn’t around? Like he only really said it to like the chancellor guy I think so no one less rlly knows…

He's still crown prince. The emperor is still alive in a coma. It was a secret plan. When the empire invaded her kingdom, she was supposed to be captured while the others are executed. Of course she didn't know that they are trying to take her alive when it happened. She's busy being scared of getting dragged and killed.