To get to this content, you need [spoiler alert] the following endings: Ciri becomes a witcher and Radovid conquers the northern realms. After you tell Emhyr that Ciri is dead, you go back to White Orchard. While on your way to get her a new sword, look for Tomira's burning house to the right of the road. You can see the location in the video. This is not exactly a quest, but Tomira is not somebody you'd want to see burned at the stake.
