He was stuck in staring mode again. No reason to get upset? He had every reason to be upset! His sister was on the ship, and who there knew how to adjust her medication? No one, that was who. And whining? He thought he was handling this remarkably well.
He had a feeling that attempting to explain any of that would just be seen as more whining, so Simon kept his thoughts on the matter to himself. They probably wouldn't have come out coherently anyway. His worry for River was eclipsing most of his concerns aside from the immediate ones of shelter and food -- which would apparently be tended to by this welcome center.
"I wouldn't want to trouble you," he replied to her offer. He wouldn't have minded an escort, but he also wasn't sure her attitude would do anything but agitate him. Maybe she'd been here long enough that this was an every-day thing and she could be so blase about it, but she also probably didn't have a concern like his that might take it on herself to crash a space-ship in a fit.