Mother of Eli Wallace. Maryann is living with H.I.V., which places a strain on her family's budget -- something Eli has helped to relieve by agreeing to sign up with the Air Force and the Ninth Chevron Project.
Maryann was a nurse, and contracted H.I.V. when she was accidentally stuck by a needle while trying to restrain a junky in the E.R. Her husband (Eli's father) couldn't deal with it, and left them. Eli was 14 years old at the time.
When Eli Wallace was offered a job by the Air Force, Maryann returned home to find him gone. A call from her son assured her of his safety, as well as the fact that the Air Force would look after her health in exchange for the work he was doing. But she grew increasingly despondent the longer he was gone, and wondered if she would ever see her son again. She was hospitalized and, though physically improving, was emotionally on the edge of an abyss.
Eli visited her using an Ancient communication stone but could not convince her he was really her son. She was eventually permitted to visit Destiny herself (using a communication stone), and saw Eli face-to-face again. She told him how proud she is of him, and was released from the hospital the next day with a new lease on life.
Air, Part 1 - Maryann receives a phone call from her son, learning that he has taken up an offer with the Air Force to provide for her health care coverage.
Time - Hunkered down in a damp cave trying to survive the night, Eli reveals to T.J. that his mother is living with H.I.V. -- the reason his father left them.
Pathogen - Eli rushes to his mother's bedside when she takes an emotional turn for the worse, but can't convince her he is her son in someone else's body -- until she is able to visit Destiny herself and see him.