Now that Susannah has tried to escape three times, a nurse mentions to Dad that if Susannah's behavior continues, she'll be moved to a psychiatric ward. Dad wants the nurses to understand that someone is looking out for Susannah, so he decides to spend his days outside her room reading a book, since she still believes he murdered Giselle and won't see him.
By deciding to sit outside Susannah's room, Dad finds a way to show his love for his daughter and support her on her terms, despite the fact that his presence is a thing she absolutely doesn't want right now.
Dr. Russo alters her diagnosis from seizures to just psychosis, as Susannah hasn't had a seizure since she was admitted to the hospital. Dr. Russo also suggests in her notes that Susannah be transferred to a psych ward, both because she's no longer experiencing seizures and because she's a difficult patient.
Though Dr. Russo sees the absence of seizures as evidence that Susannah might not actually be physically ill, the tone of this passage suggests that the stopped seizures are a symptom of something much larger.
Mom visits on her lunch breaks and when she gets off work. She and Dad also start a shared journal to communicate about Susannah with each other, as they still find it hard to be in the same room even after being divorced for eight years. When Stephen visits, Susannah appears to relax and become calmer. The second night he visits, however, Susannah tells him that she understands if he doesn't come back. Hearing this, Stephen vows to stay by Susannah's side.
Mom and Dad's shared journal shows that they're willing to put aside their differences for Susannah's sake, as their love for her trumps their difficulties with each other. Stephen's decision to stick with Susannah is a similar kind of pledge to support her, even though this is certainly very difficult for him.
On Susannah's fourth day in the hospital, several more doctors join the team, including Dr. Friedman. Dr. Freidman attends to Susannah's dangerously high blood pressure, and speaks to Dad in the hallway after his examination. Dad describes Susannah before she became ill, and Dr. Friedman assures Dad that Susannah will improve. Dr. Friedman embraces Dad, and Dad cries.
Susannah describes her dad as a stoic, private man. Because of this, his crying episode with Dr. Friedman illustrates how terrifying this experience is for him, and how his unconditional love for Susannah isn't altered by her desire to not see him.