Karen Peterson was the next door neighbor to Jack and Jan Jordan, and frequently baby-say for their twins Jason and Jennifer. When Jack’s cousin Hal Jordan came to stay with them for a while, Karen and Hal hit it off. Hal asked Karen out on a date, and when the villain Casey Jones broke into the museum they were visiting, Karen discovered that Hal Jordan was actually Air Wave. Instead of revealing that she knew, she kept Hal’s identity a secret.
Karen and Hal continued to date, as the both of them attended first Taylor High School, then Texas University. She continued to baby-sit the Jordans', and secretly helped out Hal’s super-hero career. When the young Jordan twins discovered and almost destroyed Hal’s Air Wave costume, Karen repaired it, improving a bit on its design. She secretly helped Air Wave defeat the Cosmic Corsair, and constantly protected his secret identity, especially from the Jordan family.
Eventually, Air Wave left Texas to join the Captains of Industry, leaving Karen behind. Karen’s fate after Air Wave is unknown.