Here is the full list of all 31 Queen At Arms achievements.
Romance Head Archer Cesca.
Romance Prince Alastor.
Romance Prelate Lucius.
Romance Knight Lorimette.
Romance Mechanist James. (Thanks for naming this one, Fiogan!)
Romance Archmagus Rubus.
Learn the truth of King Kendrick's legacy.
Take heavy losses at the Battle of Arendy. (Your King is disappointed...)
Minimize your losses at the Battle of Arendy. (Your King is impressed!)
Mysteriously killed by bandits after a high-profile confrontation.
Spend years in prison, then get crowned.
Someone avoids a death sentence.
Complete Chapter 4 after siding with Queen Charlotte.
Gain the throne after a trial and execution.
Hesitate to claim your crown.
Romance Spymaster Fox.
Complete Chapter 4 after siding with Alastor.
Claim the throne as ruler of Orthera.
Complete Chapter 3.
Shrapnel bombs are a great idea... right?
Ask Rubus to set the forest on fire, you pyromaniac.
Complete Chapter 2.
Volunteer to lead the charge across the river.
Wait too long to attack.
Accidentally kill a group of Ortheran soldiers.
Complete Chapter 1.
Use fire magic to aid a wounded soldier.
You died!
Run away with Nick.
Save Prince Alastor from wolves.
Get slapped.