Sheila is introduced as an employee at Harvard University that Louis Litt invited over to assess Pearson Hardman when the university wanted to rescind the firm's recruiting privileges from them, after a survey showed that the firm's associates were unhappy. Soon after that, she started relationship with Louis Litt; in episode "Stay" she finally got steady with him. Sheila and Louis got engaged, but they ultimately broke up, as Louis wanted children and she did not.
In season 5, it comes to her attention that a man named Mike Ross is claiming to be a Harvard graduate while no such records exist; Sheila then writes an anonymous tip via email to the U.S Attorney's office, opening an investigation on Mike and the rest of Pearson Specter Litt. After Louis confronts her, she realizes that he was aware of the fraud, and dismisses him; however, she tells him that she won't come forward. Regardless, the U.S Attorney's Office finds out that it was her who sent the email.
While Louis believes she went back on her word, she tells him that they found her. In order to prevent her from being on the stand and testifying, he buys her a ticket to Argentina and tells her to stay there until Mike's trial is over, as the U.S government cannot subpoena her from there. While she initially refuses, he tells her that Harvey has no qualms about revealing the fact that she and Louis were in a relationship once, and that she left him alone in the Harvard file room after having sex with him, and that she might have done that with others as well, which would cause her to lose her job. Tearful, she accepts the ticket and decides to go to Argentina.
She eventually returns, meeting a man and getting engaged. When her fiancée moved to New York, she followed him, leaving Harvard for Columbia. Louis later meets the man, Xander Epstein, another lawyer at another firm.