|Eren! What are you thinking?! Do you have any idea how many people have died outside the Walls?!|
|— Carla to her only son, Eren|
Carla had brown eyes and black hair. Her hair was rather long, kept tied loosely to the side on her right shoulder with a dark red tie and only a few short hairs around her ears and forehead were loose. When she was seen inside her home, she wore a cream-colored sweater with frilled sleeves and a long red skirt with a white apron and small tan boots.
When Eren wanted to join the Scout Regiment, Carla forbade him on the grounds that it was too dangerous, showing her motherly care. She seemed to genuinely care for Eren's safety, and had been known to be protective of her family, enough to put them before herself when Eren and Mikasa were in potential danger for attempting to rescue her. However, once her children left earshot, she whispered that she did not want them to leave her alone to die and continued crying until her death.
During her youth, Carla worked as a waitress in a bar that Keith Sadies frequented. One day, Keith brought along Grisha Jaeger, who had recently been found lost outside the Walls. Carla reprimanded Keith, thinking that he wanted to beguile Grisha into joining the Scout Regiment, but both men denied this.
Sometime later, Carla became ill with a disease that plagued most of Shiganshina and was urgently taken to Grisha by Keith, who had become the main doctor overseeing the cure of the plague. Carla was more worried about her parents, but Grisha ensured her that everyone would be fine. Grisha later managed to save both Carla and her family, and Carla hugged him as she rejoiced in tears.
They soon fell in love and later got married. Sometime later, they had a son named Eren. When Keith returned from an unsuccessful mission as commander, he approached Carla with a young Eren as she expressed her and Grisha's worry for him. Out of spite, he accused her of being ordinary and lacking in imagination. Carla listened to Keith and then simply stated that some people do not have to be special or greater than anybody else. Carla then claimed that existing on its own was very special.
Carla is first shown tending to the Jaeger family home. Mikasa speaks of Eren's desire to join the military and Carla becomes very upset, scolding him on the dangers of the Scout Regiment. Though his father, Grisha, remained passive and became curious of Eren's ambition. After Grisha leaves the house on business, Carla again attempts to convince Eren otherwise. This leads him to yell at her and run off, ignoring her protests. Upon this, Carla tasks Mikasa with looking out for Eren, saying he needs to be protected from himself.
During the invasion of Wall Maria, the Colossal Titan breaches the Wall of Shiganshina District by kicking at its outer gate, and some of the flying debris falls on the Jaegers' house, destroying it with Carla inside. She is trapped and her legs are crushed. Eren and Mikasa attempt to free her, but they are not strong enough to lift the beams holding her down. She begs them to leave because of the Titans swarming the city as one Titan is visibly approaching their house.
Soon, Hannes arrives, initially declaring that he would save the three of them from the approaching Titan, despite Carla's protests that he should grab the children and run. However, Hannes loses his nerve at the frightening appearance of the Titan and decides to take the children to safety instead, abandoning Carla under the wreckage as she requested.
Against Eren's desperate protests, Carla screamed to her children that she loved them and pleaded them to stay alive. Once the three were on the run and out of earshot, Carla mutters that she does not want them to go, but covers her mouth with her hand so that the children cannot hear her last words. The Titan pulls her from the debris and squeezes her in its hand, causing her innards to spew out of her mouth. Just after Mikasa looks away, it devours her as Eren watches in horror.
While Eren recuperates after the Assault on Stohess battle, he remembers when his mother told him that he is a man who needed to show some restraint and not get into fights, with Mikasa always coming to his rescue. She reminded him that he also needs to be there for Mikasa. She would later be avenged by Eren, when he used the Coordinate ability to make the Titans attack and devour the Titan that killed her.
- Grisha Jaeger - Grisha was Carla's husband. Keith introduced them, which worried Carla by thinking that her friend tried to recruit Grisha to the Scout Regiment. He was a well renowned doctor known most notably for single-handedly curing an epidemic that had affected the town. She fell in love with Grisha after he was able to cure her and her parents of a life-threatening disease, and soon married Grisha. When Carla learned that Eren wanted to join the Scout Regiment, she pleaded Grisha to change his mind, but Grisha said that there was no point in stopping an inquisitive mind like Eren's. In Eren's memories of Grisha injecting him with the Titan serum, Eren tells him in confusion that Carla's death drove him insane.
- Eren Jaeger - Eren was Carla's only son. She felt a deep love for him, seen when she told him not to join the Scout Regiment because it was too dangerous. Knowing her son is too reckless for his own safety, she often took care of him with Mikasa's help. Also, when she was trapped under the debris of their house, she ordered Eren and Mikasa to run away and leave her behind so that they could escape from the Titans. She also told Hannes to take them and run, feeling relieved and thanked him when he accepted. She would be avenged by Eren, years later, when he indirectly killed the Titan that killed Carla.
- Mikasa Ackermann - Carla relied on Mikasa to keep an eye out for Eren, trusting her enough to pull him out of trouble. When Mikasa was first accepted into their home, Carla showed that she was comfortable with Mikasa's company. The two often did chores together in the home such as washing dishes and they bonded over this. Carla relied on Mikasa to keep an eye out for Eren, trusting her enough to pull him out of trouble. When Mikasa struggled to save her, and when she was taken away, Carla painfully called out to her in her final moments, worried for her safety. She greatly cared and worried for Mikasa, despite her independence and strength. Carla's death had a deep impact on Mikasa who vowed to uphold the promise she made to her in protecting Eren.
- Keith Sadies - Carla knew Keith from his regular visits to the bar she worked in, becoming friends over time. However, she was often annoyed when Keith tried to convince customers to join the Scout Regiment. Though it is hinted that Keith had strong feelings for her, she seemed to be always unaware of his thoughts. Still, Carla respected him and was worried about the dangers that he experienced in the Survey Corps. After one of the expeditions in which she had not heard from him, she awaited Keith to scold him for risking his life. Despite the fact that Keith responded rudely, she did not seem to be offended but only momentarily surprised, and continued talking to him kindly. After her death, Keith regretted his reaction and tried to prevent her son Eren from joining the military in order to save his life, though he ended up changing his mind since Eren's wishes were too strong.
- Hannes - Carla and Hannes were acquainted for some time prior to Shiganshina's destruction. When it was breached Hannes initially tried to fight the Smiling Titan to save her but out of cowardice fled and took Eren and Mikasa with him, though Carla was thankful that Hannes took the kids to safety. Carla's death and his cowardice to stop it haunted Hannes for the rest of his life, and was ironically killed by the same Titan 5 years later.
- Carla is the first character in the series who is shown being eaten by a Titan.
- Carla has a character song in Linked Horizon's Shingeki no Kiseki album, 14 Moji no Dengon (14-Lettered Message).