Grandma-down-the-hill is Gene’s mother, and the two have a complicated relationship. Grandma-down-the-hill is not a religious extremist – she believes that her grandchildren should be in school and is frustrated by her family’s refusal to use the hospital for medical emergencies. She annoys her son by staging small rebellions, like stocking up on every flavor of milk after Gene begins to preach against drinking milk. Tara describes her paternal grandmother as “a force of nature - impatient, aggressive, self-possessed.” She does what she can to support her grandchildren and balance out their father’s more radical teachings, and even plots to smuggle Tara to Arizona where they can enroll her in public school. Although Tara is deeply under the influence of her father as a child, Grandma-down-the-hill helps to plant contrasting ideas in her mind about college, working women, and other ideologies, building a small foundation on which Tara can eventually stage her rebellion.

When Grandma-down-the-hill is diagnosed with cancer, her relationship with Gene becomes increasingly tense. Gene doesn’t support his mother receiving medical treatment for her cancer, and he pushes her to turn to Faye’s herbal remedies instead. After Grandma-down-the-hill dies from her illness, Gene even goes so far as to say that she was unsavable because she had turned away from Christ. However, in the immediate aftermath of her death, Gene is emotionally devastated by the loss of his mother. Although they weren’t fully estranged when she died, the two were unable to reconcile their differences in the years leading up to her passing, and this failure weighs on Gene. He becomes moody and depressed, clearly struggling emotionally to cope with the loss. Grandma-down-the-hill is yet another example of Gene pushing loved ones out of his life due to his radical beliefs. His strained relationship with his mother mirrors his relationship with his daughter Tara. His extremism makes it impossible for him to reconcile with his loved ones.