Angela is one of the twelve members of the group established by Adam Monroe thirty years prior to the events of Kirby Plaza. The other twelve members include her husband Arthur Petrelli, Daniel Linderman, Robert Bishop, Maury Parkman, Kaito Nakamura, Charles Deveaux, and Victoria Pratt. It is implied in "Lizards" that Angela had a sexual relationship with Kaito Nakamura.
Before the start of the series, not much is known except that she had two children with her husband of forty-one years, Arthur Petrelli: Nathan (whom she raised on her own while her husband was at war) and Peter. She and her recently deceased husband had been protecting Claire with the Haitian's aid.
During the events of "Six Months Ago", Angela arrives at Peter's graduation party with Nathan and Heidi, Nathan's wife. She informs Peter that his father could not attend because of a meeting with Atlantic City and congratulates Peter for graduating from nursing school. There were enough lawyers in the family, she explained; she always wanted him to be a nurse. Since learning of her husband's death, she has become increasingly blunt and free to speak her mind.
In "Genesis", Angela is picked up by New York Police Department for shoplifting a pair of socks. While Nathan worries about how it will affect his campaign for the United States Congress, Peter sees it as a cry for attention. Angela tells Peter that Nathan "only cares about himself," and that Nathan and the deceased Mr. Petrelli were "alpha dogs".
After Peter is hospitalized, due to his fall in "Don't Look Back", she confesses that his father did not die of a heart attack as she had claimed. Instead, he committed suicide after two previous failed suicide attempts. She worries that Peter may be developing the same depressive tendencies and confesses that he was always her favorite child.
A few episodes later Angela and Heidi plan a family brunch at Nathan's %28Heroes%29” title=”Godsend (Heroes)”>Godsend", Angela and Nathan sit in a comatose Peter's hospital room. Angela is worried sick that Peter is going to die of a heart attack. Later, when Nathan finds Peter gone, she tells him that Peter woke up in a rage and left. She is angry that Peter could keep her worried for two weeks and then just leave, saying she will kill him when she finds him. In "Run" alt="" />", Nathan worries that Meredith Gordon will tell the press about Claire, their long-lost, illegitimate daughter; he wants to meet Claire, but Angela persuades Nathan not to meet her, instead paying Meredith to keep quiet.
In "Parasite", the Haitian calls Angela saying in French, "Yeah, I've got the girl. What do you want me to do? I see… Marseille." Claire Bennet escapes the Haitian and arrives at Peter's apartment in New York, seeking Peter's aid. She is greeted by his mother instead. Angela, calling Claire by name despite the two having seemingly never met before, informs Claire that she came at a bad time, but invites her in anyway. Once inside, Angela chastises the Haitian in French. Surprised, Claire asks Angela who she is—Angela reveals that she is Claire's grandmother. Angela amusingly notes how Claire was so determined to get to Peter, going so far as to run away from the Haitian. She says that Claire's stubborn streak is just like her father's.
In "Mohinder brings Peter's body to the house. Distraught, she sends Mohinder away. When Nathan arrives, she persuades him to hide Peter's death until after the election. After Claire revives Peter, Angela interrupts a conversation between Peter and Nathan. Peter begins to explain about his abilities, but Angela tells them both that she knew long before they did.
In "The Hard Part", Angela reveals to Nathan that she has been working with Linderman. Regarding the bomb, she explains that "a lot of people put time and care into making this a reality, myself included," and urges him to have faith in his destiny (to become President). She finally persuades him by asking rhetorically "Can you be the one we need?" (the same request that future Hiro made to Peter). Even though she is allied with Linderman, this has not stopped her from keeping Claire out of the hands of Linderman's Company.
In "How to Stop an Exploding Man", Peter sees Angela conversing with Charles Deveaux at some past instance during the early days as caretaker of Mr. Deveaux. The two appear to be old friends and discuss the plans for the future. Angela supports the plan for Nathan to rise to power after the explosion. Deveaux conversely believes Peter's kind heart will be the key to saving the future, to which Angela reveals that she does not think that Peter is capable of such greatness.
In "Four Months Ago…" she tries to scare off Nathan's wife, Heidi, by telling her Nathan's condition is related to the condition that drove Mr. Petrelli to suicide and urges Heidi to keep quiet about the whole thing for Nathan's sake.
In "Four Months Later…," Angela is confronting Nathan over Peter's 'death' (although it is later revealed to the audience that he is alive). After being ordered out of the apartment, she finds a torn photograph of herself with a red helix drawn over her face (indicating her future demise). The person on another piece of the photo, Kaito Nakamura, is brutally murdered that night. His photograph was marked in the same fashion as Angela's.
In "Lizards", Angela was taken in by New York Police Department to be questioned about the murder of Kaito Nakamura. It is revealed through the questioning that she was a major stockholder in the failing Yamagato Industries, leading Parkman to press on whether she killed him for money or sex. She responds by denying both and adding that she hadn't slept with Nakamura "for a long time". Later, an unknown person attacks her in the interview room but Parkman saves her. In Angela's hands is a piece of picture, ripped from the same picture as Kaito Nakamura's piece, with the helix symbol on it.
In "The Kindness of Strangers", she retracts her assertion that she is innocent and admits to killing Nakamura, though Parkman realizes she is lying to cover someone. The wounds she sustained are described as self-inflicted. After she is taken in, Nathan and Parkman team up to decipher the identity of the killer.
In "Cautionary Tales", Matt Parkman uses his newly-discovered mind control power to have Angela brought back in for questioning. He uses his power to get her to tell the truth, attempting to ascertain the identity of the one masterminding their murders and the nameless woman on the photo of the Company's founding members. Despite her resistance, as well as her claim that he'll be no better than his father for his efforts, he learns the name of the woman.
In "Powerless", Parkman and Nathan confront Angela about the truth of the virus. Though reluctant to divulge the information, Nathan's accusation of her generation's deeds punishing his future convinces her otherwise. She also gives Parkman specific instructions to kill Peter if he can't be reasoned with. After Nathan is shot at his press conference, Angela has a telephone conversation wherein she states that there was no choice but to shoot Nathan. She then comments that the action "opened Pandora's Box."
 Alternate Future
In "Out of Time" when Peter accidentally teleports into a virus-stricken future he is taken to see Angela. After they embrace, Peter pushes Angela away and asks if he should know who she is. She tells him she's with him to help him remember who he is, or the virus will kill everyone it hasn't already killed. When Peter remembers Angela is his mother, she tearfully embraces him again. Later, as Angela escorts Peter out of the facility, she proclaims that they're going home. Peter sees Caitlin behind a chain link fence and tries to get a hold of her, but then inadvertently teleports back to the present and away from Angela.
In this Volume, Angela is updated as a main character rather than a recurring/supporting character.
In "The Second Coming", Angela reveals to Future Peter that her power is that of dreaming the future, explaining that Peter's first ability was absorbed from her. In "The Butterfly Effect", Angela becomes the head of the Company after the death of Bob Bishop; her first on-screen action is to fire Bob's daughter Elle, stating that she was only kept on the Company books at her father's insistence. After Sylar is recaptured, she tells him that she is his real mother, and that she gave him up for adoption.
In the next episode, Angela partners Noah with Sylar, much to the former's dismay. While they successfully capture some of the escapees, Sylar kills Jesse Murphy for his power and is placed back in his cell.
In "Angels and Monsters", she encounters Peter in Sylar's cell, the former having just snapped the latter's neck. Peter loses control and begins to open up Angela's skull, but Sylar wakes up and throws him against the window, knocking him unconscious. Soon afterwards, she puts Peter in an artificial coma, and reveals to Nathan and Tracy Strauss that Nathan's ability was artificially induced. Nathan is naturally disgusted with her, and she later has a vision of Tracy, Peter, and Nathan being brutally murdered by Arthur Petrelli. Angela insists that she will stop him, but he tells her that she won't even be able to move. She wakes up from her dream, paralyzed.
In "Eris Quod Sum, she appears to Sylar while he is in the coma in which Peter imprisoned him. She tells Sylar to save Peter from Pinehearst, and to show her why he is her favorite son. Sylar awakens from the coma and kisses his sleeping mother on the forehead, agreeing to rescue Peter.
In "It's Coming", Matt Parkman is able to journey inside her mind, where he finds her handcuffed to a chair. He tries in vain to free her, but she reveals that even if he can remove the handcuffs, Arthur has locked all exits from her prison. Arthur then appears to Matt in the guise of Daphne Millbrook, and proceeds to stab Matt. Matt is forced to bring the real Daphne into the prison, and she reveals that she is in love with him. Angela then reminds Arthur that they had once felt that way about each other, and he reluctantly frees her. She is allowed to leave with Daphne and Matt, waking up from her coma. She is soon reunited with Peter, Nathan, and Claire in her hospital room. With her forces gathered, Angela tells them about the formula, revealing that there is a third piece required: a catalyst which hosts in the blood of a human being. Kaito Nakamura was the only person to know the host's identity. When Angela finishes explaining, Claire informs them of her belief that she is the catalyst, as Sylar saw something different inside of her.
In The Eclipse Part 1, Angela sends her team out on recruitment missions: Nathan and Peter off to Haiti to find the Hatian; Matt and Daphne to find Hiro. She also sends Claire into hiding with Noah to keep her from falling into Arthur's hands. Later, she spots Tracy having a phone conversation with someone (whom the viewers already know is Arthur) and grows suspicious.
In "The Second Coming", Angela reveals that she has the power of precognitive dreaming. She says that this is also the first power Peter ever overtly demonstrated. Further demonstrations of her ability have shown that it goes beyond merely seeing the future, as Peter uses it at one point to visit the past, and Angela uses it to enter Sylar's dreams.