Lucy Gray Baird made a colorful, chaotic splash into the world of Panem during The Hunger Games: The Ballad of Songbirds and Snakes. Unlike Katniss Everdeen, the protagonist of the original films, Lucy Gray knew how to work a crowd, loved to perform for others, and wasn't much of a physical fighter. Their fates also proved to be wildly different. Katniss helped end the Capitol's tyrannical regime, ended up having kids and staying with her love interest Peeta, and spent her life balancing the good with her PTSD and past trauma. Lucy Gray, however, ended up vanishing without a trace, and nobody in Panem ever knew what became of her.
Source:https://www.cbr.com/ballad-of-songbirds-and-snakes-lucy-gray-perfect-ending/