Meredith was once a wonder-child and employee working for Stark Industries, working in a force field against Iron Man's Repulsor technology, reason why her prototype was destroyed by him. She was approached by Arthur, who offered her a place in his technological brotherhood called The Circle. She became the main creator of new technologies for the Circle.
During an auction run by A.I.M., the Circle bought part of the replicated Extremis technology, and Meredith created new and better exoskeletons for their own purposes. After they noticed Iron Man was in the search of the Extremis which A.I.M. stole, Arthur proposed Stark a wager, if Stark defeated the Circle's Extremis-enhanced pilots, he would be free to retrieve the Extremis.
During one of the battles, Stark tried to destroy the Circle's Extremis sample, which was brought to the battle field, but failed because it was being protected by one of Meredith's force fields.
Anyways, Stark realized that the force field was light-permeable, being able to penetrate it and destroy the Extremis sample by using a potent U.V. laser, thus the Circle lost all the Extremis they had left, being unable to continue producing new technologies.