@IndanaBegum Let's see. The doctor, of course, is the one that diagnosed her, so naturally he knows. And he knows that she knows, because he told her the prognosis himself. The king also knows because she told him, and had the doctor provide the evidence.
In Chapter 10 someone overhears the doctor speak to his assistant about the princess' death, and that's when rumors of her impending death start to spread. Not the specific disease, just that she is sick and will die soon. Then on Chapter 11, the doctor is asking for help from the duke, and specifically mentions that the princess has Raphaelis. This is heard by the duke, of course, by Eugene, who was with the princess and reacts with shock, and the princess herself. So now the duke and Eugene know she has Raphaelis, and Eugene at least knows that she knows because they heard it together. Emphasized by the fact that immediately Eugene becomes kinder to her. Also, she knows that Eugene and the Duke both know that she has the disease, since they both heard it at the same time straight from the doctor. So there's really no need for her to bring it up.
And in Chapter 12 we see that the duke knows that the princess knows, because he noticed her overhearing his conversation with the doctor.
I don't feel like going through the remaning 24 chapters since Emma shows up very sporadically, and mister angel is some kind of intelligence operative so he should be aware of the rumors of her impending death. I just don't recall if he found out the exact disease before now.
So the duke and Eugene knew, and they knew she knew. Which makes their reactions in this chapter strange.