couple of quick thoughts. Yes, it is HOT here, but we do walk around outside here, some of us quite a bit, some of us even continue to hike. It would seem impossible to a tourist, but it absolutely happens. We get accustomed to it, and it is dry. That said, do I think she walked anywhere really? no, just wanted to say it is not completely out of the realm.
Also IMO - if there was someone in the canal, they'd have been found pretty quickly.
Sadly, I think she and her baby have been secreted away by someone with bad intentions.