Exactly. The "problem" with prenups is that no one knows what would happen in the future and that what is fair under some situations (For example: no children), might be unfair if that circunstance changes. Also, people might go into marriages with different set of expectations that they haven't even discussed. As the number of childrens they want or who is expected to care for them.

Prenups should take into consideration lots of topics and cover the most common ones. As in "is a SAHP" who have signed separate finances entitled to demand that their spouse pays for a father's surgery? Theoretically, if the spouse says no, that's it. But if the SAHP has been doing everything agreed on and even making concesions, would that be fair? Or the other way around, the working spouse has a health problem and loses his/her job. Should he/she compensate the other part? Depends on the rest of circunstances. There are many things in life out of our control. Prenups should have "caveats" or exceptions for some of them (within reason).

Jessica might have been better signing the pre-nup, but at the same time, if she hasn't complained about new outcome (I don't know if she has complained or not), then she is being consequent with her choice. Without knowing that much about that couple but based in what you said, it seems that the greedy one is her father, not necesarily her. By the way, I can't understant why his father needed to "let her sign" something if she was an adult. Was she? The father involvement is what seems more shady and weird in that example.

Anyway, if other kind of contracts are revisited after previously set amounts of time, pre-nups should follow a similar logic for the benefit of both parts. And yes, signing to keep things the same is always an option. But renegotiating seems just logical.