I’m not surprised the neighbors or other locals didn’t report KB missing. I’m KBs age and while I don’t have a child, my whole life consists of my career and when I get home, that’s my sanctuary. I don’t really know anyone around, save for a couple people at the dog park, and I think they would assume I was busy at work or on a short trip if I didn’t show up with my dog for a week. No one knows me well enough to be concerned.
Now, my phone and social media use is a different story. Within 24 hours someone would sound the alarm, likely lots of someone(s). So that part is different, unless KB has virtually no online presence either, and maybe text a couple of close friends every several days or so.
I guess as odd as it seems, it’s really not beyond the realm of possibility.