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Orla is the older sister of Nimue. They both appeared as little children in a future scene in Baptism of Fire in Wyrwa, a small village somewhere in the Northern Kingdoms. Together with other children they gathered round and listened to old Stribog. He recounted Geralt's adventures from the past. Both girls wished to hear more about the love story between Yennefer and Geralt.
This scene has no influence on the current events of the novel.