The elder of two fraternal twins, respectively a girl and a boy, Marla began her life in rural Ontario. In most respects, she was a pretty ordinary kid, though lack of active parenting caused her to decide as a small child that all authority was overrated. Under what was mostly her bad influence, she and her brother Melvin grew up shattering windows, egging houses, and generally causing the worst of mayhem in a close-knit, six-thousand-population town that was hardly used to such trouble. Their parents were confronted, but they in turn did little but give their kids slaps on the wrist. They weren't neglectful in the material sense of the word - they made sure the house was more than an empty nest in terms of stacking necessities - but as far as actually raising their kids went, they were happy as long as hell, their two offspring stayed out of jail.
This began to change when Marla's father took a new job and relocated his family to the States. In a huge city like New York, it was suddenly much easier for Marla, now fourteen, to find mischief in places that had no guarantee to be as "tolerant" as her old town. Concerned mostly about safety, the mother realized this, sending Marla and Melvin to separate high schools as a start to try and reduce the former's terrible influence on the latter. In that sense it worked: in those four years, brother and sister drifted apart as each formed their own separate circles of friends and interests. Marla, however, found plenty of new ways to get into trouble all by her lonesome. Thanks to the types of people she hung around at school, this could mean anything from vandalism to shoplifting to drug-sampling. Luckily, the last of these didn't stick, as she accidentally overdosed on crack in her first exposure, and the subsequent hospital visit and talking-to she received ensured she'd never purposely try anything like that mess again. Not to mention crack was gross anyway.
In her senior year, she pulled it together and scraped decent enough grades to land herself in a small local college. Sucked into the "drugs to help me stay awake, then drugs to help me sleep" cycle, she built up an incredible tolerance for caffeine during these years - as well as a completely unintentional addiction to OxyContin, which she got over only with some trouble. It was also during that same year (not long after she broke the OxyContin habit) that she accidentally discovered something else about herself. She had the power to make herself, apparently, not visible. The first time this happened she didn't think much of it, since it happened in the company of rather drunk friends, but after a while it dawned on her that she had a problem: she couldn't make herself visible again. Oh, no. Her friends, when they sobered up somewhat, also realized that one from their number was missing and rang up the cops after conducting a private search.
All her disembodied yells of "I'm right here, just invisible", however, eventually just caused those friends to grow very irritated as far as becoming convinced she was just playing a stupid game or prank. They knew it wouldn't have been beyond her personality. Left alone, Marla stole back into her dorm at night to collect some money, cards, and clothes before disappearing- this time for real- to work out her own problems. Namely, the Help I'm A Ghost one, though in the meantime - hey, it couldn't be so bad, right? She could have some fun with her newfound trick before going back.
…Or so she thought. Days became weeks in the blur of city life, and weeks drew on into months. Still she didn't try rejoining the rest of society again; she found she was having too much fun with what she could do, namely in various forms of petty thievery and unrelentful pranking. It actually wasn't long before she figured out how to twist the "on" switch and become visible to other people again, though the first couple switches thereafter were a little rough, especially when they happened at inopportune times - say, when she was in the middle of nonchalantly hauling an armful of items she wanted out of a busy store. Times got better, though. As her control over her ability solidified over time, her confidence accordingly shot way up. The world was her oyster as long as she used her head and wasn't too stupid or obvious.
After the bomb went off, Marla found herself briefly reshuffling priorities. Little brother, where art thou? Though she spent a decent amount of energy looking, it was an unmercifully short time before she got sidetracked - if he was still alive, she could always find him later (she'd been out of contact since high school anyway), and in the meantime, there was all this lovely stuff that would be all gone if she didn't join the rush to ransack empty buildings now. It was this activity that eventually caught the attention of representatives from the Linderman Group. She became involved with them off and on, accepting payments for burglaries and odd jobs that took advantage of her special gift for stealth. Though she never got to the point of calling herself a regular employee, she did build ties with a number of the group who were. To this date, they remain one of the few people who really know how to get ahold of her when she's wanted; otherwise, she's just a shadow among the millions of other people living in New York City. A shadow with sticky fingers.