What is on the back of Lois seat?
She can see *through* the seat -- and see her own mother's heart beating. It would probably be too much of a psychological shock, if Gracie saw it.
That would explain how Emma knew the heart had stopped, in this next quote --
She knelt on the jacket, the rocks painfully gouging her knees, and reached toward Lois's wrist. She felt a trembling hand on her arm. She turned toward Emma, to see her lip quivering in her white face. "It's stopped. Karen, it's stopped."
"*What*?" Karen grabbed wildly for Lois's wrist, and felt frantically for a pulse. She couldn't find it; Emma was right, the heart had stopped. Immediately she was full on her knees, heedless of the pain. She leaned forward, and braced herself against the partially-exposed steering wheel.
