There usually weren't any kids at the base. Occasionally, someone's family would visit or kids would stay as a temporary measure, but it was never anything longterm.

So, Ralph is fairly surprised at first when he sees Newt in the forest. It takes him a moment to remember that a kid had come in on that recent ship.

It sounded like she had been through something pretty rough, so he's a little surprised that she's out and about.

After a moment, he decides to talk to her, "Hey, whatcha doin' there?"