I think this comes somewhere in the middle.
The baby is healthy.
That's what he tells her, and Mal's standing there, just outside the door, and it's all he hears, though he's sure Simon's said other things, about ultrasounds and nutrition and not getting killed for the next eight months, at least. He doesn't hear what Zoe says, though her voice sounds strange, low and thick and not like herself. He supposes it must be a shock, after the last little while, after all that mess and death and noise, now suddenly there's this notion of quiet and patience and newness, inside her. Mal is in shock, himself, and he thinks Simon's voice sounds strange, too. Not nervous. Happy. Surprised, though with all the gadgets and learning the boy's had he sure gives the illusion of control and predictability. Mal bets the doc hasn't gotten to give good news, much. Knows he hasn't, all his time on this ship.
Supposing it's good news.
He peeks around the corner of the door, sees Zoe's face, warm and sad and staring at her hands on her belly, where he can't see any difference.
It's good news.
There's also a scene where they take River on a train. There are mines involved. And a swamp. And predictions of the future.
I really, really don't have time for this. o.O