At age 18, Amanda Krueger (1907-1968) decided to become a nun, choosing "Mary Helena" as her name in Christ. Her first assignment as a nun was to care for the inmates in Westin Hills hospital, including the infamous tower (where the most insane patients were locked up). Only a few days away from Christmas, Amanda was accidentally locked in the tower when the guards were in a hurry to go home to their families. She was left alone with the inmates for several days, and she was brutally raped and beaten many times during this ordeal. When she was finally found, she was barely alive — and pregnant. Nine months later, Amanda gave birth to Frederick Charles Krueger (aka Freddy Krueger). Shortly after, the infant was given over to the state and adopted by Mr. Underwood, an abusive alcoholic. Amanda Krueger followed her son's trial after he was arrested for the murders of several neighborhood children. Freddy was released on a technicality and Amanda was distraught, committing suicide shortly after she heard the news. Amanda's body was never found. The tower where she hanged herself was sealed and that wing of the hospital closed. A head stone was placed in the Springwood cemetery for "Sister Mary Helena".

Amanda Krueger would return twice, in spirit form, to help those that were fighting her son Freddy. Her first appearance was in Dream Warriors. Amanda appeared as an old nun going by her name Sister Mary Helena, trying to help doctor Neil Gordon save the last Elm Street children. At the end Neil found her grave site and learned Freddy's mother had been helping them. The second time was in The Dream Child. After his defeat in the The Dream Master, Freddy used Amanda to give birth to him again in the dream world. Upon his return, he remained afraid of his mother's power and tried to keep her sealed away. Alice Johnson, the heroine of the film, needed to find Amanda's resting place so that this power could be used in the fight. She did not have enough time to search, so she had her friend Yvonne try and find the body. The body was found and Amanda's spirit was freed just in time to help Alice defeat Freddy. After his defeat, Freddy was left in his infant form, which Amanda then absorbed back into her. Eventually he escaped, continuing his reign of terror in Freddy's Dead.

In Freddy vs. Jason vs. Ash: Nightmare Warriors, Amanda is seen among the Dream Warriors—after Jacob Johnson becomes the new Dream Master following his mother's death (Alice Johnson).

In Marvel Comics' non-canonical A Nightmare on Elm Street comic series, Amanda appears in a flashback depicting her rape and impregnation by the inmates of Westin Hills.[5] Additionally, Innovation Publishing's Nightmares on Elm Street miniseries mentions her, with the implication being made that Freddy has rid himself of her permanently.[6] Amanda makes a cameo appearance in the three-issue comic miniseries A Nightmare on Elm Street: Paranoid by Avatar Press; Amanda appears in the Dream World being attacked by dream versions her rapists as Freddy laments the fact that he cannot reach the children of Springwood to her ("That ain't fair, ma!")

In Westwood Studios' A Nightmare on Elm Street computer game for the Commodore 64 and IBM Personal Computer, Amanda appears throughout the game, dispensing hints and health to the player.[7]