Austin69403
commented
4 years ago I figured out that is has to do with your most recent party leaders. The last (I wanna say 5 or 6) family members that are used to form parties are the only ones you're allowed to turn into your heir. Strangely, the only way I got it to work and turn my daughter into my heir was by sending her off to fight looters by herself, then getting captured by them. While she was captured I sent one of my sons on a solo party mission and waited for him to get captured. and once she was free ONLY THEN would she appear on the form a party list, and then I waited for the time it took for me to die and she was finally an optional heir.
I kinda don't like how your brother and sister are forced onto you, but my main complaint is the limit to how many potential heirs you can have, I just spent so much time trying to deck out my first born daughter, only to find out that I CAN'T choose her as an heir, it's just not possible. I'm not sure if there's a limit to potential heirs or what, but I know I have the same problem whenever I try to make her a party leader. For some reason she just won't show up on the list, along with my other daughter. (My wife and sister are totally fine though), and then my two ugly ass looking sons who are also potential heirs that I just spent the past hour trying to get killed before my main character died just so hopefully a slot opens up. (if that even is the problem I REALLY don't know since my two sons seem to be fucking immortal.)