As long as your prenup meets Texas state law requirements then it will be enforceable in a court of law. This means the prenup:
Was signed voluntarily by both parties
Was signed prior to the upcoming marriage
Fully discloses financial obligations and property of both parties (unless one party waived their right to disclosure in writing)
Has terms that are not unconscionable or does not create hardship for either party
It is important to remember that there are some things a prenuptial agreement does not cover. Those include:
Child custody
Child support