Little is known of the early life of Wanda Wilson before she was rescued from a river into which she had leapt in an attempt to commit suicide by Terry Sloane in early 1942.  Pulling her to shore, Sloane - himself somewhat suicidal - asks her why she had attempt to take her own life and invites her to unburden herself. She shares that after the deaths of her parents, she was raising a younger brother on her own.  The  young boy - Billie - had been targeted by small-time hoodlums and demoralized by his family's modest lifestyle, been swayed by them into joining their gang.   Wanda attempts to confront the criminal leading the thugs but is ridiculed and rebuffed.  Feeling she had failed her brother and her parents' memory, she resolves to take her own life.  Sloane is moved by this story and in a crystalizing moment, finds his own renewed sense of purpose. He created the identity of Mr. Terrific and broke up the gang, putting Billie and his friends on a better path as members of a Fair Play Club (Sensation Comics #1).  The Fair Play Club's history beyond the first few weeks of it's formation is largely unknown. 

Shortly thereafter, Wanda visited Sloane and revealed her deduction that he and Mr. Terrific were one in the same (Sensation Comics #2).  He confides in her that she has guessed correctly and offers her a position as his admin assistant, helping organize his affairs while serving as a Man-Friday for Mr.  Terrific.  For example, she helps him expose a bribery racket by disguised herself as an old woman to pass out fake bills (Sensation Comics #4) and accompanies him to a banquet to cover for Mr. Terrific while he exposes crimes (Sensation Comics #7).  In return, Mr, Terrific solves a case in which she is accused of murder (Sensation Comics #14) or helps her improve the life and self-esteem of a well-to-do spinster who has been repeatedly jilted (Sensation #21).  Her enthusiasm to be included sometimes befouled Mr. Terrific's case work such as when her interference allowed Mr. Laff to escape in his initial encounter with Mr.Terrific (Sensation Comics #12) or when she keeps a diary of her life with Mr. Terrific that ends up stolen (Sensation Comics #47)   She also encountered some share of the dangers of Mr. Terrific's life such as when she is kidnapped by Mr. Futile (Sensation Comics #46) or is caught up in a fake stock company she is doing extra work for (Sensation Comics #19).