Suzanne Collins' The Hunger Games prequel, The Ballad of Songbirds and Snakes, gives readers new insight into Coriolanus Snow, the Dark Days and the beginnings of the Hunger Games. Fans also meet a new cast of characters in both The Capitol and District 12. While there are no mentions of any Everdeens, and Katniss never brings up any family members older than her parents, fans speculate that Katniss is related to Lucy Gray Baird.
Source：https://www.cbr.com/hunger-games-katniss-lucy-gray-related/
