Bonnie's father sexually abused her as a child.
Bonnie Winterbottom escorts Gina Sadowski, a woman charged with the attempted murder on her boss and lover, Arthur Kaufman, into the office of Annalise Keating so she can tell her side of the story to the professors law students so they can come up with a defense, which will help her walk free. After Annalise explains the competition to the students, she tells them they can get help from her associates, Frank and Bonnie. After Frank introduces himself to the class, Bonnie introduces herself, explaining that she'll like the students more if they come to her with answers instead of questions. When the students present their ideas, Bonnie and Frank help Annalise determine who will go through to the next round. After the winners are chosen, the court sessions start. Bonnie sits in the sessions on the defense desk, and she is in charge of most of the evidence and facts for the case. When Connor Walsh presents an illegally obtained email that will help the case, Annalise uses Bonnie to help confirm its legitimacy in court...and it works, impressing Connor. Later that night, Bonnie and Frank stay at Annalise's office while the professor and her selected students attend a formal party with Sam Keating, Annalise's husband. Annalise and Sam return to the office as Bonnie and Frank work. Bonnie, over friendly, greets Sam and gives jealous looks towards Annalise as she kisses her husband. Later on, Bonnie witnesses Frank flirting with Laurel, so she wants him to stop "screwing the students". The following day, after learning Gina bought aspirin the night before the attempted murder, Annalise is upset with Frank for not getting that bit of information out of the client. They end up winning the trial; however, Nate is later brought in to testify. Bonnie is then present when Annalise reveals who will come to work at her firm. She gives Frank suspicious looks when it's revealed Laurel is one of them.