[citation needed] Muellerleile played the role of Sophie, a waitress, in the film Return to Me, directed by and starring Bonnie Hunt, and then later appeared as a series regular on Hunt's comedy series, Life with Bonnie, as Gloria, the housekeeper, for two seasons until the show ended.
She also played the nanny on Melrose Place and a no-nonsense mother hosting a Halloween party on Highway to Heaven.
Also in 1984, she appeared in the hit comedy film Revenge of the Nerds as the pedophilic woman who answers the door where Harold Wormser goes to ask about the room for rent.
Muellerleile recurred as a nun-teacher Sister Dominick at the school of the characters Madeline Fitzpatrick and London Tipton in The Suite Life of Zack & Cody episodes Forever Plaid, Books & Birdhouses and A Kept Man.
and had a role in Smokin' Aces as Margie Turlock, where she treats shooting victim Hollis Elmore (Martin Henderson) after a botched drive-by attempt by the "Tremor Brothers".