Sophie was a less-than-honest aspiring actress who appeared in the ninth season, when she befriended and briefly lived with Steve Sanders. Despite knowing that Steve had a crush on Sophie, a reluctant David began a secret relationship with her. Once this matter was unveiled, the friendship between the two men became briefly strained. Ultimately, though, the two made up while talking the issue out, with David declaring that the long-standing friendship was more important to him. At this point, Sophie had left both of their lives and continued her show business pursuits.
As Beverly Hills, 90210 and Melrose Place exist within the same continuity, the casting of Laura Leighton in the role was seen as a bizarre move by the producers, as she had had already made a name for herself playing Sydney Andrews, a major character from Melrose Place. However, after it is revealed in the 2009 revival of Melrose Place that Sydney was alive, having faked her death in 1997, rumors sparked that Sophie Burns could have been Sydney Andrews all along.