von Hohenberg, daughter of Franz Ferdinand, was a real person. She was not an archaeologist turned psychic, she was a European aristocrat. I'm sure they are completely different people.
At the end of the Austria, 1908 episode, Old Indy tells his psychiatrist that he did meet Sophie
again, but "that's a story for another day". I've done a lot of research, trying to find out when that was so I could write the lost tale
. I haven't come up with an Indy connection yet, but here's
more information about her.