She was played by Karen Duffy.
Lloyd Christmas is a simple-minded limousine driver in Providence, Rhode Island. Harry Dunne, Lloyd's roommate and buddy, is a part-time self-employed pet groomer who drives the "Shaggin’ Wagon", a van converted into what looks like a shaggy dog. They plan to open their own pet store that sells worm farms, though their lack of finances are troubling them. One day, Lloyd becomes infatuated with his passenger client, Mary Swanson, on her way to the airport and ultimately home to her family in Aspen, Colorado. Mary intentionally leaves a briefcase in the airport terminal for some thugs to pick up. Lloyd, not knowing it is a ransom payoff for her husband, rushes in and grabs the case thinking she accidentally left it, but is unable to catch her in time. Later that night, Lloyd convinces Harry to break out of their mundane lives and drive to Aspen to find Mary and return the briefcase, also hoping that they may gain greater prominence with society. On their trail are two thugs, Joe "Mental" Mentalino and J. P. Shay, who both saw Lloyd grab the briefcase.
On the way, the two run into several misadventures, though they manage to wriggle their way out of them: a tough redneck named Sea Bass bullies Harry and attempts to sexually assault Lloyd, though they narrowly escape; a motorcycle cop pulls the van over and attempts to cite them with DUI, but accidentally drinks Lloyd's urine; Joe manages to hitch a ride with Lloyd and Harry and is intent on killing them with rat poison, so as to retrieve the briefcase, but ends up eating the pills himself when Harry unwittingly feeds them to him; finally, approaching the Colorado border, Lloyd mistakenly re-enters the interstate headed eastbound for several hours while Harry sleeps. The two have a heated argument after realizing Lloyd's mistake, but the latter makes amends by trading in their van for a scooter. They head on to Aspen, but once there, they are unable to locate Mary. The two again scuffle in a park, but when they discover the contents of the briefcase, they check into a luxury suite and purchase a Lamborghini Diablo, promising to return the money in I.O.U.s.
The two finally track down Mary by attending a community function, with Lloyd planning to ask her on a date. However, he makes Harry do the task, as he is too nervous himself. Mary becomes smitten with Harry, whose stupidity she mistakes for intentional humor. The two make plans for the next day, and Harry untruthfully tells Lloyd that she will be waiting for him in a bar. The next day Harry and Mary have fun skiing, while Lloyd is left waiting at the bar for over three hours. When he uncovers the truth, a vengeful Lloyd immobilizes Harry with laxatives and meets Mary at her house. The two then head for the suite where Lloyd shows her the briefcase, and he attempts to engage with her. However, the mastermind of the ransom operation, Nicholas Andre, who is actually a long time confidant of the Swanson family, arrives and holds them at gunpoint upon discovering that his ransom money is gone. Harry returns, but is taken hostage as well. The FBI arrives in the nick of time to save the day with Beth Jordan, a woman Harry met earlier at a gas station, leading the way as a surprise undercover agent.Nicholas and J. P. Shay are both taken to prison.