I was working with a couple recently. Each spouse had children from a previous marriage, and they wanted to make sure their estates were set up the right way to protect themselves, their spouse, and their children - the right way. They knew there was the potential for conflict when they die because the sets of children did not know each other very well, and we all know what happens when people who do not know each other well have to share an inheritance!
The couple had a pre-nup from before they got married about 20 years earlier. Note that pre-nup can also be referred to as "Marriage Contract," or "Separate Property Agreement." They also had old Wills. Some of the provisions of the Wills were in conflict with what the pre-nup stated.
This led me to want to educate you about the difference between the two. In general, the purpose of the pre-nup is to determine who owns what. In the typical pre-nup when spouses get married later in life, and they each have their own children, the spouses will want to deviate from the presumed community property regime, and they will want to keep everything as separate property - what the husband has and what the husband earns during the marriage is HIS, and what the wife has and what the wife earns during the marriage is HERS. So it is real clear who owns what when one of them dies (or, if they get divorced) - no community property. The pre-nup is not the place to say who gets what when you die. In Louisiana, each party is represented by a separate attorney, each party signs the pre-nup, and it is typically recorded at the courthouse. It's a contract.
The Last Will, or the Revocable Trust, dictates who gets what when you die, and who is in charge of the administration and distribution. The WIll or Trust is not the place to try to control what is separate and what is community. Sure, your assets may retain their community or separate property status when placed in a trust, but the WIll or Trust should merely be used as a vehicle to dispose what you own, not declare what you own with your spouse.
Too many times we see conflict between the provisions of the Marriage Contract and the Last Will or Trust. You are asking for trouble if that is the case. Make sure you understand the role of each so that there will be a simple and quick estate administration when you die, with everyone (and the lawyers) being clear on everyone's rights.