No, they do not. Prenuptial agreements were designed for couples to sort out property matters, in the event of a divorce or the death of a spouse. Couples may not predetermine solutions for child custody or support. Many states limit or forbid spousal support waivers within prenuptial contracts – see the Spousal Support page for information about contractual alimony in Texas.
Parties must know the difference between separate and marital property to understand what can be included in a Texas prenuptial agreement. Separate property belongs to one owner. Disputed marital property is up for division by state community property laws, unless a pre-marital agreement redefines property status.
Prenuptial contracts deal with debt as much they do with assets. Debts are property, too, and subject to division as separate or marital obligations. Prenuptial agreements may be employed to restrict debt liability and distribute debt in ways that are beneficial, or at least less financially aggravating, to spouses.
A prenup can be used to protect assets, like heirlooms and anticipated inheritances, that you wish to remain with relatives in your bloodline. The agreements also can include provisions to shelter assets for children from earlier relationships. Keep in mind prenuptial agreements are not substitutes, but supplements for estate planning documents.
Asset and debt management during marriage can also be spelled out in pre-marital contracts. Details can be included about how specific accounts, taxes and marital bills are handled and how responsibilities are divided. You can include planned investment strategies to reach significant financial goals like business or home ownership.
Every legal document has its limits. You cannot include anything in a prenuptial agreement that conflicts with laws. Attorneys can offer alternative contractual solutions for any issues that don't "fit" in a prenup.
Just as each marriage has unique qualities, so do prenuptial agreements. Each spouse enters marriage with different viewpoints and property concerns. Resolving financial matters in advance of marriage may ease worries about the future.
Source: FindLaw, "What Can and Cannot be Included in Prenuptial Agreements" Aug. 26, 2014