Life before Xavier's
Laurie is a second-generation mutant. Her father, Sean Garrison, from whom she received her power, used his power to manipulate people and get money, fame, and women. Laurie's mother Gail was one of these women, and stayed with him until the day his power stopped working on her because she was pregnant with his child. Leaving him after learning what had happened, she raised Laurie alone. Laurie, realizing her mother had been hurt, became a quiet loner, until one day, while on vacation, she suddenly became very popular due to the emergence of her power. Her mother (who was immune to her pheromones), realized this, and tried to talk her down gently, but Laurie became scared of what she could do and ended up even more withdrawn than before.
Student at Xavier's
After the Xavier Institute became public, Gail decided to send her there, and moved to Salem Center to stay near her, so that she could have one person whose reactions she could trust. Although she insisted she live at the school, to try to make her come out of her shell, it didn't work. Laurie went through several roommates very quickly, and stayed quietly in her room, panicking, while a riot was going on, hoping she wasn't the cause. When Sofia Mantega came to the school, she was paired with Laurie and, given her ability to blow Laurie's pheromones away, Sofia didn't have to worry about being accidentally manipulated by Laurie. Refusing to let her stay in their room, Sofia started hanging around with Laurie, as did David Alleyne and Kevin Ford, with Laurie and Kevin developing mutual crushes. Then, when on a visit to meet Sofia's "dad" (not her real father, but his manservant who'd had more time for her than her real father ever had), they got into a fight with the Reavers, and Laurie was stabbed through the chest, mortally wounded. She was only saved when Josh Foley, one of the Reavers who had just discovered he was a mutant, healed her (she quickly developed a crush on him), while Kevin, enraged, tried to kill Donald Pierce, the Reavers' leader, by withering him away with his power. Dani Moonstar was forced to make him confront his worst fear - killing Laurie - to make him stop, and he left the school shortly after. Laurie continued to stick around with the future New Mutants - and was happy when they were joined by Josh. And less happy when he developed a big crush on Wolfsbane just as Sofia was urging her to ask him out. When Josh was out late one night, breaking curfew, she thought she heard him approach and sneaked down to let him in... only to find him eviscerated by an out-of-control Wolfsbane, driven temporarily insane by the return of her powers. Controlling her power for the first time to scare Wolfsbane away, she nonetheless could do nothing for Josh's apparently mortal injuries. As he was rushed to the Institute's infirmary, she was depressed at the thought that she'd finally managed to control her powers properly too late to save him. But, when David and Surge managed to think up a way to get him conscious long enough to heal himself, she was needed to keep him calm long enough for him to do it. They succeeded, although she was hurt by the fact that he obviously still had a crush on Rahne.
After the mansion was destroyed and rebuilt, she was placed on the official New Mutants squad with Josh, Sofia, David, Surge and Kevin (who Dani, with the help of Emma Frost, had managed to persuade to return) and she was given the codename Wallflower with an "it fits". When Sofia crashed and burned (figuratively speaking) in her first Field Day as leader, Laurie found her crying in their room after some harsh criticism from Josh. Laurie offered to speak to Josh - saying that she could talk to Josh about Sofia, even if not to ask him on a date. Trying to pluck up the courage to talk to him, she came across him just after he'd been turned down by Rahne again, who felt a relationship with him was inappropriate now she was on the faculty, and he asked if she wanted to him, and after she'd mentioned the "Sofia thing", he suggested they get some dinner in town - on their own (making neither Rahne nor Kevin, who still had a crush on her even after she'd moved on, happy). Going to a video arcade, she confessed to Josh about what her father was like, and how she didn't want to be like him, and that that was why she'd "avoided everybody." Halfway through saying that she had her powers mostly under control and she should be dating, he finally clicked that she did want to date - him. As they were leaving the arcade to go somewhere else, Rahne interrupted to bring them back to the Institute: the FBI had caught up with Kevin about his accidental killing of his father. After the school, buoyed by reassurances by Agent Pierce over the clearly accidental death, allowed Kevin to be taken away by the FBI, Laurie was one of the most upset, and went to skim stones on the Institute's lake. Icarus found her, having already gathered the rest of the New Mutants - barring Sofia - with the news that the rest of the Hellions had gone to break Kevin out, and that Sofia went with them. Laurie's reaction was "Good!", but the others talked her into helping them stop the Hellions: although she was even more annoyed after Josh tried to get Wolfsbane to help them. She used her powers to keep Rockslide crying and out of the fight while the others fought around them, until the X-Men - alerted by Rahne - turned up and took them all back to the Institute. The charges against Kevin were dismissed, but, soured on the New Mutants, he swapped squads with Icarus (although he and Laurie remain friends - if strained by her crush on Josh) - while, unbeknownst to her, Josh and Rahne covertly resumed their relationship. Eventually Rahne, feeling it would be healthier for Josh to be with Laurie after she saw the two returning from a date, broke off her relationship with Josh for good - unbeknownst to either her or Josh, in front of Kevin. Eventually, Kevin used the information to break Josh and Laurie up, and Laurie was left embittered by the experience, going so far as to use her pheromones to manipulate Prodigy into kissing her at the dance in a successful attempt to make Josh jealous, which might have gone unnoticed but for Sofia realizing what was happening, and the event added to the fast disintegration of the squad. Thereafter, Sofia pushed all the New Mutants into a camp out for one night on the Xavier Institute grounds. While the initial attempts by Sofia at forcing a resolution came to disaster when a fist-fight between Josh and David led Laurie to confess to Josh what had happened at the dance, later she - along with the other New Mutants - overheard him pouring his heart out to Icarus, leading her to forgive him enough to be friends and telling David she didn't know how to apologize to him for her behavior at the dance, saying she just didn't want to be the weak one any more, and he forgave her.
Decimation and death
After the House of M crossover, where almost the entire mutant population lost their powers, Laurie was one of the lucky few who retained the mutant gene. Kevin Ford mistakenly believed he had lost his powers and reached out to Laurie, withering away her arm. Shortly after this trauma, Laurie was shot and killed by a sniper working for the Reverend William Stryker. It is later revealed that Stryker had her killed because a vision from the future foretold she would be the one to single-handedly defeat his army.
Laurie mysteriously returns in Astonishing X-Men when Emma Frost locates her in a crowd of people and attempts to reach her, questioning her sudden reappearance. Upon reaching her, "Laurie" explodes and transforms into a bio-sentinel.
Powers and Abilities
Empathic Pheromone Manipulation: Much like her father, Wallflower generated highly-potent airborne scent-based pheromones, which affected the chemical balance in other people altering the moods of those around her. Initially, she had no control over this at all, and she would cause everyone within range to match her moods. Recently, she could control it to an extent, but still had lapses when her emotions were particularly strong.
Wallflower possesses the ability to use her empathic pheromone-based powers to alter the emotions, senses, perceptions, and thoughts of her opponents. She was even declared by ONE to be an Omega class threat.