Ciri's Room is a short Side Quest found in Velen, in Crow's Perch, after you have completed the Bloody Baron and Ciri's Story: King of Wolves quests.

After speaking with the Baron, and agreeing to help him find his loved ones in exchange for information on Ciri, you can actually explore the room where Ciri stayed at in the Baron's residence.

On the first floor, head right from the entrance and enter the room on the right. Geralt will realize that Ciri stayed here, and you can use your Witcher senses to look around. Note the bloodied clothes she left behind, the odd book on The Natural Obscurity of Curses, and the spinning top on the floor. The top belongs to Gretka, the girl Ciri saved in the woods. Leave her room and enter the kitchen on the other side of the hall.

Here you can talk to Gretka and ask her for more information on Ciri's whereabouts. Although she cannot give any concrete details, she will make some interesting comments, and be delighted at the return of her toy that Ciri carved for her.

For your trouble, you'll receive 100 experience for completing the quest.