To the OP, OP's MIL, and OP's wife - I feel for you guys. I had a similar situation many years ago with an elderly, terminally ill relative who meant a lot to me where everything was recorded and confirmed ahead of time - no cell phones and in a new country, my relative, even with a travel companion, was given no assistance and not even a spare wheelchair for the companion to push while in transit at PHL. I do hope your MIL feels better soon.

While I think we'd all like to believe we'd offer your MIL our personal help if we were at the airport and encountered her, I think this is a reminder for us to all have a little patience and compassion for infrequent travelers and others around us who need our help.