The first Donna was an accounting employee of Strickland Propane. She appears, albeit infrequently, as a heavy-set, dark-skinned woman, most notably in "Meet the Propaniacs". In "Are You There, God? It's Me, Margaret Hill", Buck mentions having discovered stolen office supplies in her bedroom (presumably during an extramarital encounter), and orders Hank to "find us a new Donna". She appeared in staff photos, and since Maria Montalvo does not appear with the rest of the staff, the first Donna can be easily mistaken for her.

Meet the Propaniacs

Strickland Propane Christmas Card