Alternative idea...
After the Raid, you could ask Duncan, (who was in charge cleaning the dungeon) if he could return the elf weapon... (You then can use it to gain some of her favor with the princess, or just give her signature weapon when the main story is over) (duo to whatever choice with the princess, the elf will be yours anyway...)
Maybe a bride to the armory guy who Duncan sends you to retrive the bow...
It could happen though... simplier and easy