You know, I'm not sure why they haven't explained more to Mikan. She already knows about the time travel and the dragon. She has god of fortune glasses. So other supernatural stuff won't be as big of a shock.
And we know that she's not going to tell everyone about it like the mc thought she would in the early chapters. The evil queen persona is a facade, and she only puts private stuff in the paper that she either has permission for or fabricated.