During the 70th Hunger Games, Annie witnessed her fellow district partner being beheaded, which drove her to insanity. After she saw her district partner die, Annie broke off from all other tributes and hid for the rest of the Games, until an earthquake broke a dam and flooded the entire arena. Having grown up in District 4, Annie survived by being the best swimmer. Since then, she has been perceived as being mentally unstable because her district partner was beheaded. She has certain problems which includes closing her eyes and covering her ears, laughing when it is unnecessary, and staring into the distance at strange times. It seems that the only person who could calm her was Finnick Odair. Annie was the only true love of Finnick, who was the victor of the 65th Hunger Games.
In Catching Fire, Annie was reaped to participate in the 75th Hunger Games, but Mags, an older tribute, who mentored Finnick and Annie during their Hunger Games, volunteered to enter the Games in her place. After the jabberjay attack in the arena, Finnick tells Katniss about Annie.
In Mockingjay, Annie was arrested by the Capitol and was supposedly tortured. Finnick explains to Katniss Everdeen that they didn't take her as hostage because she had information about the rebels; the Capitol perceived Finnick would never endanger Annie by telling her anything, and took her simply as a weapon to use against him. After Finnick suffered a mental breakdown, a group of rebels broke into the Capitol and got her out; taking her safely into District 13. Upon her arrival, Annie was reunited with Finnick and the two embrace.
In District 13, she and Finnick become publicly married in the traditional District 4 style. Their wedding cake was decorated with waves and dolphins by Peeta Mellark. Annie wore the dress Katniss had worn in District 5 on her Victory Tour. Katniss notices that, since their marriage, Finnick does not let go of Annie's hand and that Annie seems "lost in some daze of happiness." Later on, Annie and Finnick meet Katniss, Gale, Johanna, Beetee, Delly and later a rehabilitating Peeta at lunch. When Johanna tells Peeta that they are familiar with each other's screams, she covers her ears. Katniss figures that Annie is not all that bad, just maybe a little unstable. Peeta jokingly tells Finnick to take care of Annie or he will take her away from him.
Later on, Finnick suggests to Peeta (and Katniss) that he ask what's real and what's not real; claiming that's what Annie does when she tries to remain sane.
On a mission to infiltrate President Snow's mansion, Finnick is decapitated by several lizard mutts. Katniss describes how she watches his life flash by as if she were Finnick (which includes seeing Annie in her wedding dress.) Katniss tries to kill the mutts, but she was too late to save Finnick.
Before President Snow's planned execution, President Coin gathers the seven surviving victors. She asks if they would like one final Hunger Games using children of the most powerful people in the Capitol in retribution for oppressing the Districts. Annie, along with Peeta and Beetee, vote no, Annie additionally commenting that Finnick would have voted with her against the final Hunger Games. However, Enobaria, Katniss, Haymitch and Johanna vote yes; outnumbering Annie, Peeta and Beetee. At President Snow's execution, Annie watches Katniss kill President Coin when she was supposed to kill President Snow.
Annie returns to her home in District 4, where she gives birth to Finnick's son. She sends Katniss a photo of him to be put into her book.
Annie suffered from Post Traumatic Stress Disorder due to her terrible experiences in the Hunger Games. Katniss Everdeen described her as 'strange' but stated that she was not mad, as most others believed, simply unstable and seemed to like Annie since they kept in touch after the war was over. Annie would occasionally withdraw into herself so that it seemed she was in a different place which would result in her staring into space with a blank smile on her face until she was brought back to reality. She sometimes laughed when there was nothing to laugh about and closed her eyes and covered her ears with her hands to block out the memories from the Hunger Games. When she was reaped in the 75th Hunger Games, Annie started screaming hysterically. Only Finnick Odair was able to calm Annie down when she started having a fit.
Although Annie had some severe mental difficulties, she was very kind-hearted and forgiving, voting no when President Coin suggested doing a 76th Hunger Games using the Capitol's children as tributes in order to punish them for three quarters of a century of tyranny and terror. She did not seem to be dangerous and despite the fact that her mental problems were caused by the Hunger Games and the love of her life, Finnick, was killed by the Capitol, she showed no interest in revenge. As it is not stated that Annie was a volunteer Career Tribute, she may not have actually been, even though she came from a Career District. It is assumed that the only reason she survived the Hunger Games was because she was a stronger swimmer than the other tributes, suggesting that she may not have needed to directly kill anyone.
Annie was married and widowed by Finnick Odair, the former victor of the 65th Hunger Games. They had one son. She has no other known family.
The two had a deep love for each other. Finnick mentored Annie, and most likely did everything to keep her alive. During the interview with Caesar Flickerman, Finnick recited a poem for Annie ('his one true love' he said), but almost every woman in the Capitol thought the poem was aimed towards them. During the third Quarter Quell, Finnick heard Annie's screams during the jabberjay attack because she was who he cared about above all others. He was worried that they had hurt Annie. In Mockingjay, Finnick constantly worried about Annie and could not concentrate on anything else but her. He was out of his mind because Annie had been captured by the Capitol so they could torture her for information about the rebels. To set his mind straight, he tied different knots with a foot of rope and brought it everywhere with him, hoping to regain sanity and distract himself from worrying about her. He broke down when he couldn't handle it anymore and soon after, the rebels rescued those captured by the Capitol including Annie. Finnick and Annie reunited in District 13. Later, the two get married and conceive a son. Finnick died before Annie gave birth to their son.
It is safe to assume Annie and Mags knew each other well, and Mags was likely her Mentor alongside Finnick. Both were described to be Finnick's family, so they may have been close, as Mags volunteered as tribute to save Annie and clearly knew she would never survive.
Annie is described as a lovely young woman with flowing brown hair and sea green eyes. Katniss describes her as 'lovely if somewhat bedraggled' in Mockingjay, although no doubt bedraggled due to her recent imprisonment. She is thought to be in her early 20's, as mentioned when Mags volunteered to take her place for the third Quarter Quell.
- Annie and Haymitch were the only known victors that were still alive after Mockingjay to not be in the 75th Hunger Games. However, they were both reaped and volunteered for.
- Annie has mental problems, including covering her ears and closing her eyes, laughing at unnecessary moments and staring into the distance randomly.
- As it is not stated that Annie was a volunteer Career Tribute, she may not have actually been, even though she came from a Career district.
- It is stated in The Hunger Games Exhibition that Annie is 23 years old, making her 18 at the time of her victory.