Nikki filed a name change petition, representing herself pro se, on February 9, 1996 in Houston, TX. In the name change petition she requested to change her name from:
Nikki Paige Purdue
Her later name change to Nikki Araguz occurred as a result of her marriage to Thomas Araguz in 2008. However, from 1999 to 2007 she used the name Nikki Purdue-Mata, when she was married to a man named Emilio Mata who she divorced in 2007.
In the section for name change reason, her petition states:
I, Justin Purdue, am a woman with male anatomy, working toward a sex change. I have been living and working as a woman for over one year and seek to make my new name legal and permanent.
(source - name change petition)
Elsewhere in the name change petition at the link above, it states that Nikki was born in Carmel, California on June 4, 1975. This is significant because the California birth place accounts for Nikki's ability to have obtained a new, female, birth certificate at some point. According to the information on the "Dr. Becky" web site, California is one of various states that issues new clean birth certificates to transsexual people after they have had surgery and are able to present appropriate documentation of that fact to the state of California. The following site contains detailed information about the process: