I don’t understand why these two are fight lol, they both hate the Speroror family. I understand that the Duchess saw the letter as a threat and the Dowager [?] However, It Seems Medea to have just genuinely wanted to warn her. It sad that she was married of to the kingdom that killer her parents though, know wonder she is bitter and she has every right to be. However, all royal marriages are based on politics and power, not love. The Dowager is in her legal rights to choose a family she thinks will be beneficial for her son….either by hook or by crook within monarchy law. Keeping power only towards the family is the based of a monarchy in the first place.
Also the Dowger shares the name of the MC from "to be you for a day"