Re: My father in law flipped
A prenup with him? Crazy and meaningless. If you get married to her and she inherits or is gifted lots of money (or a house, car, diamond jewelry, etc), it is not yours if she keeps it in her name. No prenup needed. Anyone would be smart to keep an inheritance separate from joint property. If you go all stupid and cheat on her with a house full of hookers, you wouldn't get any of her inherited property when she decided to divorce you.
On the other hand, as things go well in the marriage, there is no reason she couldn't use some of that money to pay bills or buy you gifts (e.g. a car).
It is common practice to keep inherited or gifted wealth separate from joint property. No big deal, and I would not be insulted if I were engaged to a wealthy woman if she let me know this is how things were going to be.
Her father can easily set up a trust (and he should, and probably already has) which stipulates how his estate is managed and disbursed after his death.
The bigger question now is whether you want to get involved in this family, and what new things do you learn about your fiance in the next little while as a result of her father's actions.