Pauline Cohen signed a prenuptial agreement before she got married. When she later challenged the validity of that document, both the New York County Supreme Court and the Appellate Division, First Department, were unwilling to cut her any slack. Neither court thought her pregnancy rendered her mentally incapable of agreeing to the terms, nor was her husband's ultimatum to sign the agreement (or the wedding would be cancelled) seen as "duress."
Although the papers were in French (Pauline's native language), and executed in France, the agreement was still enforceable in New York because it had been prepared by an "independent public official" and otherwise met all the governing technical requirements.
That was some Family Affair.
To view a copy of the Appellate Division's decision, please use this link: Cohen v. Cohen