When her telekinesis powers first manifested, Martha "Sully" Sullivan daydreamed playing the role of a new super-hero, Mind-Over-Mattie. She later tempered those goals, choosing instead to incorporate her "powers" in creative and professional channels as an technical consultant providing special effects in movies and television shows.
Sully grew up in Astro City. She first discovered her powers when she was fourteen years old. (Their exact source is unclear, though her best theory is her mother's exposure when pregnant to a mento-field during a fight between Professor Borzoi and the Gentleman). Her first thought was to become a superhero, Mind-Over-Mattie, but after a few nights on patrol, she realized she didn't have the mental constitution for such a risk-filled vocation.
In the summer before college, she went to Las Vegas to try her hand at being a supervillain instead. Her plan was to use telekinesis to win at slots, but just one jackpot was enough for her to know she couldn't deal with the guilt. The young girl was torn up inside, possessing superpowers but completely confused as to what to do with them.
After college, she moved to Los Angeles and became a bartender. Her co-worker was an aspiring director, and she ended up using her powers to help him with special effects for his low-budget project. This, in time, grew into a steady career doing TK-generated special effects for TV and film.
She moved back to Astro City to work on the soap opera "Tomorrow's Dawn." The show had a superhero character, the Crimson Cougar and it was her job to produce his aerial stunts. One day, she assisted her friend, Cougar actor Mitch Goodman, in preventing a local AstroMart robbery. This incident kicked off a rapid rise in popularity for Mitch and when that proved to be too much for him, even a danger to his life, Sully's powers helped him stage a PR stunt to rip his new-found glamor to sheds. ("Great Expectations")
Over time, Sully met others like her, super-powered individuals who wished to just lead ordinary civilian lives. She became part of this extended community of "Sideliners," making good friends among them.
A new supervillain, the Majordomo, once kidnapped her and various other sideliner super-types. His intent was to bring them under his influences, and then use them as part of an army for his own personal power conquests (just the latest in a list of supervillains who've tried such a thing). Sully and the others were able to escape their bonds and handily defeat him. ("On the Sidelines")
Over the years her skills with telekinesis have sharpened. Due in part to the demands that film directors have placed on her for complex and even dangerous special effects requests. She has also had other encounters that showed off not only her power at mentally moving matter, but also her leadership skills in combat situations.
Despite her passive ambitions and reluctant nature, there are times, brief and rare, when she might indeed be wondering "what could have been" if she had follow her young dreams for being a super-hero.