They have no idea what it is they've landed near when they set down, no idea who it is they're passing as walk off the ship. Serenity feels them all leave, until she's alone, just a ship waiting for her crew.

She's not a girl right now, not really, but there's a hint of her, a hint of a face in the windows, if you look closely.

Doesn't mean she doesn't notice things, though. Doesn't mean she doesn't realize the animals nearby are there, even if she has no idea what they really are, even less idea what they are to her crew.