Texian is a legitimate word. It was the term used by the residents of the Republic of Texas during Texas’ time as an independent republic. It was also used by the Anglo settlers in the Coahuila province before the war.
A zillion dollars says the OP didn’t know that.
Despite what you may think of me, I ain’t a sucker, Brutus. No wager from me.
OK, a jillion dollars. Come on, Christmas isn’t going to be cheap this year, and every bit helps…
Who says it wasn’t? 
wonders why she’s suddenly in a handbasket
“Texians”, sure. But “Texains”? You see what I mean here, Homeberw?