Cecelia was the District 8 female tribute in the 75th Hunger Games. She also was a victor from a previous, unmentioned Hunger Games. She was a mother of three, molding her personality to be sweet and good-natured. This and her motherly instincts caused Katniss Everdeen to want become her ally in the Third Quarter Quell. It was this combined with her fighting skills that caused Effie Trinket to cry out when she was reaped at the Third Quarter Quell. When she was called her children were holding her telling her to try to come home. In training, it is revealed that her fellow tribute from District 8, Woof, stayed fairly close to her. They eventually invited Katniss to the bug station, who tried asking them about the uprising in District 8. It is revealed at the end of Catching Fire that she was one of the victors who knew of the rebellion and was part of the alliance to save Katniss. However, she died before she could truly help protect Katniss.
Though it is unknown exactly how she died, Cecelia was killed in the initial Hunger Games Cornucopia bloodbath during the 75th Hunger Games most likely by a Career Tribute. She was most likely killed later in the bloodbath because of her "claimed" fighting skills by Effie Trinket. While we are unsure, she did survive the Hunger Games once before.
"...Cecelia, who looks about thirty, has to detach herself from the three kids who run up to cling to her."
- Katniss Everdeen discussing Cecelia's reaping
Cecelia was married and had three children at home by the time of the Third Quarter Quell. Their names are unknown.
Sweet and motherly, Cecelia was desired as a teammate for those traits. Cecelia was knowing of feelings, and quick to understand.