The children of the apocalypse were something special. They represented all the good things that had been, and the bright future that could still be. It was implicitly understood, then, that the children should be protected at all costs.
It made the loss of Sophia that much harder to deal with.
The survivors weren't giving her up for dead, not by a long shot. But group morale took a dive, as if reality was suddenly staring them all straight in the hairy eyeball. As long as there were children, there was hope for a future for humanity (though what kind of future it would be was yet to be said). It put them one step farther away from the extinction list, which was previously only populated by strange almost unimaginable creatures like stag-moose and wooly mammoth. They aimed to keep it that way. Protect the children, secure a future. It had seemed so cut and dry.
Funny how a day can change things.