I think as far as domestics go, Ford really started to increase their quality by the early to mid 2000s, whereas GMC and Chrysler/Jeep didn't step up their games until post-bailout, like you said. I wouldn't buy a GMC/Chevy/Dodge/Chrysler that is older than about 08 or 09, I'd be pretty comfortable going back 8-10 years on a Ford though. We just sold my wifes 99 Mustang with 150K miles on it, and it never had any issues(only sold it because we needed a family vehicle) and my 05 Escape is still going strong approaching 140K miles, have never done anything to it other than oil changes, new tires, and new batteries.
That being said, we went away form Ford and bought a new Hyundai, mostly for the price & longer warranty. Your girlfriend might want to look at a Kia, lots of Kias have 10 year 100K mile warranties, she might be able to get a cheap used one that still has quite a bit of manufacturers warranty left on it. All domestic companies only offer 3yr/36K mile warranties, those would be long gone on a used car.