Melva Jean O'Neill (née Davis) was born on October 21, 1951, in Carlsbad, New Mexico. Melva married Layton on December 19, 1979. Melva had one child going into the marriage: Amy and Layton had five children going into the marriage: Marilyn, Colleen, Mike, Jenny, and Dennis.

O'Neill was employed as a homemaker but had previously worked as a waitress and motel desk clerk.