"Do you really wish to know?" — Spoilers from the books and/or adaptations to follow!
Chloe Stitz was a professional thief from Ymlac in the employ of Dacre Silifant who was hired for Stefan Skellen's gang tasked with finding Ciri. She was widely known as an excellent shooter who never missed a shot.
During the hunt for Ciri, she was part of the group which was sent to Fano to investigate a letter sent by Bonhart to the local armourer, Esterhazy. Stitz was sometimes contracted to work for and on occasion used by the Nilfgaardian secret service.
She was shot in the back with a crossbow bolt and killed instantly by Jediah Mekesser during Ciri's escape from the village of Unicorn.