I know I'll come off as one of those people determined to keep TH a major POI, but none of this is linked to DS's activities that day, and so long as her activities aren't made clear it's really hard to read much into this. And I think most of us probably feel that way, too.
And for further discussion, the extended stop and chat isn't anything too out of the ordinary, but making a point to flip through a phone, while carrying baby K around, to show a picture of Kyron at the exhibit seems suspicious given the context of the case. We're all waiting for a flood of truth here to lead us to an innocent child, and we continue to hear second-hand bit-by-bits. At the very least, it would be nice to know what DS was doing that day.