Amanda Waller was the warden of Belle Reve Penitentiary.
In "Terrors", after a "scuffle" in the mess hall, Mr. Freeze was brought before Waller. Freeze froze the prison guard, and broke his cuffs with an ice gauntlet. Waller activated his collar, but Freeze tore it off, and froze Waller's arm before she could fire a gun. Freeze shut down the collars and cell doors, allowing the prisoners to break free. He imprisoned Waller, Dr. Hugo Strange, and the guards in the cells.
When Brick taunted Waller about being warm due to their thermal uniforms, Waller incited him. Brick grabbed her through the bars menacingly, but Hugo Strange convinced him to spare her.
Eventually, Superboy (still disguised as Tommy Terror), turned the collars back on. This angered Icicle Sr., who assumed it was Waller. He confronted her and as he was about to land a blow, Hugo tackled Icicle Sr. and knocked him out. After Superboy walked out with Miss Martian, the prisoners were put back in their cells, and Belle Reve was scheduled to be up and running the next day.
Unfortunately, the breakout attempt cost Waller her job as warden, and she was replaced by Hugo Strange.