I'm afraid of what she'd do if he actually died. Some Frankenstein's creation type of thing. Maybe transplanting his head besides her own. Jar head, perhaps.
In all seriousness it is recommended (where I live at least) to stay 24h hours in the hospital after a head trauma that made the patient lose consciousness for a while. (especially since the only person that can watch over him is a junk robot I'd say)
Sometimes hematomas in the head take a few hours to appear so it's dangerous to send him home so early.