What can I do if I live in Texas, I have a prenup before marriage a year ago, I want to refinance my house to a much lower interest rate?

I own a house, which was purchased 8 years ago. The property is in my name only and I want to keep it that way. I got married with a prenup keep my property (homestead) separate from my spouse in case a divorce arises. I am currently in the process of a refinance to half the interest rate of what I have been paying which will result in a $400 a month savings. The title company says I have to have my spouse sign a deed of trust acknowledging that I am refinancing. My spouse agrees to signing a notarized addendum to my prenup which is basically taking the same section out of my prenup word for word no changes and signing again. I am afraid that if her name is put on any other documents for this refinance i.e.; deed of trust , that it will allow her to pursue rights to my house if a divorce arises. What can I do or what documents are needed to prevent her name from being put on the title, and keep her or her children from attempting to claim any rights in the future?