As far as the Queen being the last heir:
During the human story, when it comes time for you to select an Order to join, Scholar Josir says, “We can’t allow anything to happen to Queen Jennah. She’s the last of the royal line!” which then receives the reply, “Perhaps not the last… but you’re right. Without Queen Jennah, we’d lose our treaty with the charr.” From Agent Ihan.
Interpret that as you will.