While you're in the game, go into Preferences, scroll down, and click on 'Change relationship titles'.
Thanks Lockheart, I don't remember having to do that before. Must be getting old. Actually, I AM pretty old!
One thing I found, is that I had to change MCs name as well as the relationships. When I tried to change the relationships without changing the MC's name, the changes didn't take.
Name changing and all that doesn't seem to work at the moment. Tried several times to no avail.
EDIT: it seems that it doesn't change immediately but rather sometime down the dialogue options. All set!
