Linda Carter is the daughter of a doctor in Allentown, New York. After she meets and falls in love with Marshall Michaels, a wealthy businessman, he forces her to choose between marrying him or staying at Metro General as a nurse. She makes her decision and tearfully watches him walk away. In the following two issues of the series, Linda demonstrates that her skills are not limited to nursing practice, as she performs detective work to help expose an incompetent surgeon and also prevents a hitman from murdering one of her patients. By the time the series was canceled, she had started a budding romance with Dr. Jack Tryon, a young resident doctor.
Nothing is known about the current Night Nurse's past. The only thing that can be guessed is that she may have been rescued by a super-hero once, and afterward decided to pay the super-human community back by ministering to their health. When she first appeared, she took care of a seriously injured Daredevil following his defeat by the Yakuza. Later, during Nick Fury's Secret War, Night Nurse took care of a badly injured Luke Cage (whose nearly-impenetrable skin required special treatment). During this time, the Night Nurse became known for her catch phrase "go to the room on the right," which is apparently a room in her hospital where she can heal the heroes unnoticed. After this event, she was interviewed by reporter Ben Urich, where she again stated that she wanted to repay the super-hero community by taking care of their health. Daredevil apparently took a liking to Night Nurse, because after being shot by Paladin, he asked Elektra to take him to her. Shortly thereafter, even the Black Widow visited the Night Nurse with Milla Donovan. Despite Daredevil's trust, Elektra was not impressed by the "careless" way the Night Nurse took care of her patients, and even ordered her Hand agents to teleport Daredevil away so they could take care of him themselves.
Daredevil still seems to trust the Night Nurse, because he took Spider-Man to her after he was stabbed in the neck.
Though it was at first very hard to recognize the Night Nurse in Civil War #2, Marvel Editor Tom Brevoort stated in an interview on the Internet Site "Newsarama" that it was really her welcoming the Young Avengers at the new headquarters.