She is friends with Peter Parker, Harry Osborn, Vin Gonzales, and Lily Hollister. She is one of the first potential romantic interests for Parker following the retconning of his marriage to Mary Jane Watson in the "One More Day" story arc, and eventually becomes his girlfriend.
Brand New Day
Carlie Cooper is the roommate and best friend of Lily Hollister. She is an officer of the NYPD's Crime Scene Unit. Ray Cooper, her father, was a well-respected police officer before his death. Carlie and Lily grew up together. She campaigned vigorously for Bill Hollister, Lily's father who Carlie saw as a father figure herself, for mayor.
While preparing a body found in the river for the Medical Examiner, she finds a spider-tracer in its mouth, which initiates a police warrant for the "Spider-Tracer Killer" (believed by most to be Spider-Man).
She was kidnapped by Dr. Rabin, who wanted to use her as a human sacrifice for an ancient Mayan god known as Kuhul Ajaw. Carlie is bound, gagged, and then dragged into a blizzard. But before Rabin can kill her, Spider-Man saves her and defeats the crazed Doctor.
She later discovers that the "Spider-Tracer Killer" is actually a conspiracy by a group of New York police officers, who have planted the tracers on dead bodies to frame Spider-Man in a smear campaign by turning the public against him. Carlie informs the precinct's sergeant, not knowing he is a part of the conspiracy, who has a warrant placed for her arrest, claiming that she is aiding and abetting the killer. She goes to Lily and Bill Hollister, and tells him the truth of the tracer killings. She escapes the police with the help of Menace. Later, Vin finds her and apologizes to her for all he's done.
Recently Carlie was accused of tampering with evidence, when several pieces of evidence collected from three murder scenes mysteriously disappeared from the police evidence locker. Spider-Man discovered that the 'evidence' was really pieces of the Sandman and left the evidence locker on its own. Carlie was cleared but is still looked down on by some fellow officers.
Carlie's father later reappeared, apparently not dead. He speaks to Carlie while she is watching a fight between the Magia family and Mister Negative's Inner Demons. When Carlie learns that her father was not the good cop he was made out to be, she has him arrested. She then cuts her hair and decides to be more assertive in her life.
After many near misses and almost dates, Carlie and Peter finally set up a real date and meet at the Coffee Bean. Harry and MJ happen to be there and the two girls get talking, when all of a sudden Lily bursts through the wall, followed by an attacking team of supervillains. MJ asks Carlie to help Lily, who's gone into labor, but they are held captive by Doctor Octopus. After this, Spider-Man manages to save them and rescue Lily's newborn infant from the supervillains. Later, Harry and Mary Jane take Lily to safety, but Carlie was too angry with Lily and instead focused her energy on trying to find Peter. She is confronted by Tombstone. The police arrive and Tombstone escapes, but later doubles back to follow her after discovering that Carlie knows who Menace really is. Carlie, Mary Jane, and Lily are able to defeat Tombstone when he attacks them. Afterwards, Peter and Carlie continue to hang out for a time. Carlie is fuming that Peter has not made a move on her yet. At Harry's going away party, Peter asks her to be his girlfriend. The two kiss and begin dating.
When Michele Gonzales moves back to New York, Peter considers moving in with Carlie but she decides it is too early in the relationship. It is at this time that Peter discovers Carlie is part of a roller derby team, using the sport to help her unleash any pent up anger. Her roller derby name is "Crusher Carlie".
When Peter is called out on a mission with the Future Foundation he tells Carlie he is going away on a business trip for his new job at Horizon Labs. Carlie is furious when she finds out that there was no trip. She takes her rage out in the rink which results in her being sent off mid-game for a vicious assault on "Iron Mavis" from the other side. Noticing her bad mood, two of her teammates offer to take her out for a night on the town. After getting drunk, Carlie decides to get a tattoo of the Green Goblin's insignia to spite Peter, knowing his opinion of Norman Osborn (as he had murdered Peter's first girlfriend Gwen Stacy). However, she changes her mind and gets a tattoo of Spider-Man. She is worried that the tattoo will make things awkward between herself and Peter, but he assures her that it is not the case.