Instead of going home, she teamed up with some other veterans and bribed a Gun Runner to supply her, in order to sell to her former platoon and other NCR personnel, mercenaries and generally everyone who is willing to oppose Caesar's Legion. Operating out of the back of a pre-War military truck at the 188 Trading Post, she also regularly does business with prospectors.
“Cross the bridge (there’s a long trailer with mattresses to sleep in) to the western side of the overpass, and check the tent for more mattresses. Close by is a parked military truck, with an Arms Merchant. She’s been discharged from the NCR for three years, since an “incident” during the first Legion attack on the dam. Ask her about that, as well as seeing what she has for sale (it’s usually cheaper than Michelle).”— Fallout: New Vegas Official Game Guide Game of the Year Edition p. 397
↑Courier: "What was your rank?" Arms Merchant: "Staff sergeant, Third Platoon, Bravo Company. I was at the Dam when the Legion hit us, three years back. That was a shitstorm, and don't let anybody tell you different. The brass try to play it down, but most of them were back at McCarran." (Arms Merchant's dialogue)
↑Arms Merchant: "You a merc? 'Cause you don't look like a prospector..." Courier: "Something like that. Are you an NCR soldier?" Arms Merchant: "Hell, yes ma'am/sir. Well... not officially. Not anymore. They mustered me out a year ago. Administrative discharge." (Arms Merchant's dialogue)
↑Courier: "Administrative discharge? What does that mean?" Arms Merchant: "It means my C.O. was an asshole, and I told him to eat shit. He ordered me to flog a couple 'deserters.' Those kids didn't desert. They just got liquored up on the Strip and missed roll call. I don't know what else the brass expects... half these kids don't get more than two weeks of training before they ship 'em out here." (Arms Merchant's dialogue)
↑Courier: "How did you end up selling weapons?" Arms Merchant: "Going home didn't feel right, not with those savages camped on the other side of the river, sharpening their knives. And I still get to see my old platoon when they pass through here... make sure the new C.O. is treating them right, and sneak them extra ammo. Anyway, I was always complaining about the standard issue gear. The new kids don't even get body armor, can you believe that?" Courier: "NCR doesn't have the caps to outfit their troops?" Arms Merchant: "Vegas is bleeding us dry. We're tossing caps at a hundred different problems, while Caesar bides his time and lets us wear ourselves out. Shouldn't be perched up at the Dam - we ought to be crossing the Colorado and sticking a boot up Caesar's ass." Courier: "Go on." Arms Merchant: "So I hooked up with a couple other vets... bribed a Gun Runner... Now we're supplying grunts, mercs, and anybody else on our side. We don't make much... but at least we're saving lives." (Arms Merchant's dialogue)
↑Courier: "You do a lot of business with prospectors?" Arms Merchant: "Sure do. Lots of folk been coming out east, sorting through junk, looking for whatever they can sell. Times are tough back home. Too many people, not enough work. Unless you like shoveling brahmin shit" (Arms merchant's dialogue)