Freon was the only female member of the Terrific Trio.
Mary Michaels was Mike Morgan's fiancée until the day she was exposed to the radiation that turned her into a translucent, freezing being. Together with her teammates, Mary adopted a new moniker and joined the government-sponsored team, the "Terrific Trio."
After the Trio learned the truth about their accident, they turned rogue and tried to destroy Gotham City. Batman engaged and team and activated a ventilation system, which pulled Freon in, seemingly disassembling her.
Powers & Abilities
Freon was able to fly, had a freezing touch and could shoot ice blasts.
Freon seems to be based on the Fantastic Four member, Invisible Woman. She also seems to be the opposite number of her counterpart's brother, fellow teammate the Human Torch, seeing as he can fly and has fire based powers.