In Eli’s recurring car dream, Dad is driving. Mrs. Birkbeck is presumably implying that she’s concerned that Eli and August don’t feel safe at home, since in August’s paintings, Dad is the one driving them to the bottom of the ocean. Eli gets in trouble with August because he’s opened up to Mrs. Birkbeck. At this point, it’s unclear what, exactly, Eli has told her. But the fact that Mrs. Birkbeck mentions PTSD suggests that Eli is, perhaps, healing from some sort of trauma that readers don’t yet know about.