Michelle Welton is Dr. Camille Saroyan's teenage adopted daughter. Cam was once engaged to and lived with Michelle's father, Dr. Andrew Welton, a cardiac surgeon, and helped to raise Michelle. However, because Michelle's mother died in childbirth, he was never able to fully commit to their relationship and was constantly cheating. Though Cam did love him, she ended the engagement, leaving Welton and the young Michelle behind. Ten years later, in the Season 4 episode "The Doctor in the Den", his remains are found in a tiger exhibit at a zoo. Upon learning the identity of the remains, Cam takes it upon herself to inform Michelle of her father's death. Michelle claims to barely remember Cam and treats her coldly. Later in the episode, Michelle admits she remembers and she had been very deeply hurt by Cam's apparent abandonment, and she had waited at the window for weeks, "for [Cam] to come home." At the end of the episode, Michelle and Cam are reconciled and Michelle accepts Cam's offer to move in with her.
In Seasons 5 and 6, Cam experiences frequent trouble with Michelle over such teenage issues as Michelle's new boyfriend, smoking, and school. When Michelle decides to go to a small state school to be with her boyfriend, Cam reluctantly agrees but secretly fills out an application in Michelle's name for a more prestigious university, much to the disapproval of her colleagues. When Michelle's relationship with her boyfriend falls apart, Cam reveals that she had successfully, but dishonestly, gotten Michelle into the better school. To her credit, Michelle interprets this as a test of her own honesty and decides to spend a year working and applying for the next academic year.
In Season 7, Michelle goes on a date with Jeffersonian intern Finn Abernathy after they quickly flirt while Michelle visits Cam in her work, much to Cam's dismay. On their date, they get along with each other nicely and end up sharing a kiss. They start dating despite the initial disapproval from Cam which causes Finn to back off, but Cam ends up realizing that they do really want to date so relents and allows it to continue. During Season 8 she visits Finn without telling her mother but becomes angry at Finn after Cam stumbles upon them "accidentally" and Finn admits that he told them and the 'chance' meeting with Cam had been set up beforehand but forgives him.
In Season 9 The Turn in the Urn Michelle breaks up with Finn after she admits to cheating.