Darn. That stinks. I'm sorry about that. At first thought, I'd say I haven't heard or experienced your issue. But there was a similar freeze I encountered twice many months ago--so long that I assumed it was no longer a thing and none of the playtesters every reported such.
Do you know if your sister's turn was the last in the rotation and a round event or production was going to happen afterwards? In which case, that would be the freeze I saw a while ago. It's quite elusive. If that's the case, I need to think about it more. If it's not the case, I need to *really* think about it!
Can you do send your game info & game logs to muleonlinehelp@gmail.com?
The logs are located at:
%APPDATA%\puzzud\mule\logs
And the save games are located at:
%APPDATA%\puzzud\mule\games
In the future it will be possible to resume incomplete offline games from those save game files.
Thanks for the feedback & sorry about the lost game. I spent a lot of time chasing known crashes the month before release. Unfortunately, it wasn't enough.