Warning contains spoilers
Peace as in no rebellion?
I was able to unlock two "peaceful" ending for Revaire.
- Quick rebellion where the rebels one and Sayra becomes queen (she has to confide in you her true identity and you have to campaign in favour for rebellion )
- The second option I got was the new Revaire royal family stepping down ( high enough friendship with Gisette) but in that game Sayra told me her identity too