I knew that the letter was an obvious plot device to force our girl to actually speak up, but thank goodness that something is finally going to force an end to this part of the plot. I wish our normally intelligent FMC would have noticed on her own given all the obvious hints without the brooch telling her then maybe have just been too timid to say something.
I guess that we were building to some bigger plot about the Mage Tower being a part of a conspiracy to keep the heir from being found (guessing that's why the letter says no blood relatives).