Wonderful. I'm bringing in this guy who is the king's second son - the dreaded middle child. He has a reputation for scheming to take the crown and a history of illness that has pretty much confirmed to him that he could never hang onto it even if he were to claim it. He's in cahoots with his sister, who is the real spymaster at court and mostly acts as a decoy so she can do her thing behind the scenes without anyone noticing.
If she's a lady in waiting to the princess, she would know that Hadrian and Calpurnia visit each other's bedrooms at night (not in the Lannister sense, although there are rumors) and she may have a dislike for Hadrian, who often publicly participates in snubbing/shunning Calpurnia from the more ~important matters.
Also, I have otheym, who will be a human council member and/or bannerman.