did this bed have an enclosed frame a kid could get trapped in? I know here locally a missing woman turned up inside a bed frame at the hotel she stayed in. It was foul play in this case, but nobody figured out she was in there for over a month, even though others had stayed in the same room afterward. If the kid got trapped somehow but nobody could hear her, I could see this happening.

I'm not gonna hold it aginst the mother for appearing un-emotional. If your child is missing a lot of things go through your mind until you become a zombie to the whole situation.