She stays in the Gallery. She knows she could leave; he wouldn't stop her. She could return to the world above, heal, perhaps live for a time, and die there. She doesn't fear this inevitability, but she does recognize the uselessness of it. There is nothing for her in that world. There hasn't been for some time. Here, she has herself someone previously unknown whom she can nurture and discover in this in-between place. There is nothing to fear here; she's been shown that. This place will be whatever she makes of it.
And so she stays.
He wakes, rises, goes through the motions of his morning ablutions and is halfway to the dressing area before he remembers - she is free. He doesn't have to do this anymore.
His hand flies to the wall to steady himself and he nearly weeps for joy.
She barely ever sees him. The Gallery is silent except for her footsteps as she wand