All heirs have to be their final life state before their requirements are finished. Requirements must be finished in order for heir to legally born. So the Sim would have to be their final life state before the next generation is tried for.
No heir is allowed to die. If an heir dies for any reason, then it's a failure and you either start over or keep going without being in HoF.
I have never had a Sim of mine receive a vampire bite or werewolf bite where I didn't choose for them to get that so I don't think it's autonomous for a townie to try and turn your Sim without your permission.
If you have a couple and one of them is a fairy and the other is a human but you're really wanting something like a vampire, turn the spouse into a vampire and then try for baby.
The only time I've received a human child since Supernatural came out was when a ghost was involved or a human was involved. Human spouses can be turned into everything but a witch so really you should be making sure that the spouse is the life state that you want the child to be before you try for baby. If two ghosts have a baby, you'll always get a ghost it seems. I tried this recently so if you're worried about getting a human from a ghost. See if you can sneak in some Logic skill for the ghost potion and see how that works.
In the case of a human child that you want to be something else, can it be bitten to change? Metro and I had previously talked about the moment an heir is born they are their final life state. The only one that could change was the founder but I will bring it back up with him and see where we stand on this.
Okay, so just to make sure, no heirs can change life state, only the founder can ever do that. Correct?
The reason I was concerned is I am following several Life States Dynasty stories and a bunch of them ended up with normal Sims instead of the spouse's life state, but now you mention it I think they all involved ghosts. All right, panic averted! Thanks Rica
I'll keep the Ghost Potion in mind when I get there.