The Ballad of Songbirds and Snakes marks the first return to The Hunger Games franchise since 2015's Mockingjay: Part Two. It marks the return of several existing characters ranging from the villainous President Snow to the former stylist Tigris while introducing countless new figures central to the Games' history. However, one major character remains a mystery to audiences: Lucy Gray Baird, District 12's female tribute in the 10th Hunger Games, played by Rachel Zegler in the upcoming film.
Source:https://www.cbr.com/lucy-baird-identity-ballad-of-songs-and-snakes/