Dixie got her nickname when she responded to a major drug cartel land grab in the Odessa area.  They had besieged Taurian Arms, a major arms manufacturer even back then, but the majority of the Texas Guard was down on the border engaging other cartels.  Dixie sent her refitted tanks and other drones to relieve the defenders, wiped out the entire cartel, and killed their leader.  That was the first time anybody called her Dixie the Drug Lord Slayer.